creative work on the topic "Dynamics" of the 11th grade student of the MKOU "Kirpichzavodskaya secondary school" Alexandra Fomchenkova

What is dynamics? Dynamics is a branch of mechanics that studies the causes of mechanical motion. Dynamics operates with such concepts as mass, force, momentum, energy.

Basic concepts Mass is a scalar physical quantity, one of the most important quantities in physics. Force is a vector physical quantity, which is a measure of the intensity of the impact on a given body of other bodies, as well as fields. The force applied to a massive body is the cause of a change in its speed or the occurrence of deformations in it.

Basic concepts Impulse is a vector physical quantity, which is a measure of the mechanical motion of a body. Energy is a scalar physical quantity, which is a single measure of various forms of motion and interaction of matter, a measure of the transition of the motion of matter from one form to another.

Classical dynamics is based on Newton's three basic laws. Isaac Newton is an English physicist, mathematician and astronomer, one of the founders of classical physics. The author of the fundamental work "Mathematical Principles of Natural Philosophy", in which he outlined the law of universal gravitation and the three laws of mechanics, which became the basis of classical mechanics.

What are the frames of reference for Newton's laws? Newton's laws apply only to inertial frames of reference. In these reference systems, they have the same form. V=const V=0 Y X

Newton's first law states: A material point (body) maintains a state of rest or uniform rectilinear motion until the impact from other bodies causes it (him) to change this state.

Newton's second law: The acceleration of a body is directly proportional to the vector sum of all forces acting on the body and inversely proportional to the mass of the body.

Newton's third law states: The forces with which two bodies act on each other are equal in magnitude, opposite in direction and act along the straight line connecting these bodies.

body momentum. Law of conservation of momentum.

Rene Descartes French philosopher, mathematician, physicist and physiologist. He expressed the law of conservation of momentum, defined the concept of the impulse of force. From the Latin "impulsus" - impulse - "push"

The momentum of a body is a physical quantity equal to the product of the body's mass and its speed. p = m ν p ν ; p

The Law of Conservation of Momentum The law of conservation of momentum serves as the basis for explaining a wide range of natural phenomena and is used in various sciences.

Elastic impact Absolutely elastic impact is a collision of bodies, as a result of which their internal energies remain unchanged. With an absolutely elastic impact, not only momentum is conserved, but also the mechanical energy of the system of bodies. Examples: collision of billiard balls, atomic nuclei and elementary particles. The figure shows an absolutely elastic central impact: As a result of a central elastic impact of two balls of the same mass, they exchange speeds: the first ball stops, the second starts moving with a speed equal to the speed of the first ball.

Inelastic impact Absolutely inelastic impact: this is the name of the collision of two bodies, as a result of which they are connected together and move on as one. In case of inelastic impact, the part mechanical energy interacting bodies goes into the internal, the momentum of the system of bodies is preserved. Examples of inelastic interaction: collision of sticky plasticine balls, automatic coupler of wagons, etc. The figure shows a perfectly inelastic impact: After an inelastic impact, two balls move as one unit with a speed less than the speed of the first ball before the impact.

The law of conservation of momentum underlies jet propulsion. A great merit in the development of the theory of jet propulsion belongs to Konstantin Eduardovich Tsiolkovsky. The founder of the theory of space flights is the outstanding Russian scientist Tsiolkovsky (1857 - 1935). He gave general fundamentals theory of jet propulsion, developed the basic principles and schemes of jet aircraft, proved the need to use a multi-stage rocket for interplanetary flights. Tsiolkovsky's ideas were successfully implemented in the USSR in the construction of artificial Earth satellites and spacecraft.

Also in nature...

Conclusions: When interacting, the change in the body's momentum is equal to the momentum of the force acting on this body. When bodies interact with each other, the change in the sum of their momenta is equal to zero. And if the change in some value is zero, then this means that this value is conserved. The practical and experimental verification of the law was successful and once again it was found that the vector sum of the momenta of the bodies that make up a closed system does not change.

To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Outstanding scientists: 1. Galileo GalileiGalileo Galilei 2. Isaac NewtonIsaac Newton 3. Nicolaus CopernicusNicholas Copernicus To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" class="link_thumb"> 4 !} Outstanding scientists: 1. Galileo GalileiGalileo Galilei 2. Isaac NewtonIsaac Newton 3. Nicolaus CopernicusNicholas Copernicus To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG:Outstanding scientists: 1. Galileo GalileiGalileo Galilei 2. Isaac NewtonIsaac Newton 3. Nicolaus CopernicusNicholas Copernicus To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> title="Outstanding scientists: 1. Galileo GalileiGalileo Galilei 2. Isaac NewtonIsaac Newton 3. Nicolaus CopernicusNicholas Copernicus To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> !}

Galileo Galilei () Italian physicist and astronomer. Established the laws of motion, conducting numerous experiments. He discovered the law of pendulum oscillations, created the theory of simple mechanisms. He observed the Moon and planets through a telescope, discovered the satellites of Jupiter, spots on the Sun and the phases of Venus. He supported and developed the heliocentric theory of Copernicus, for which he was persecuted by the Inquisition. Considered the "father" of experimental physics. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

Isaac Newton (1643 - 1727) English scientist, founder of modern natural science, became famous for his works on mechanics, optics, astronomy, and mathematics. He defined the three basic principles of mechanics, discovered the law of universal gravitation and, on its basis, developed the theory of planetary motion. He made a huge contribution to optics, for the first time decomposed white light into seven colors by a prism. Newton's scientific work played an exceptional role in the development of physics. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

Nicolaus Copernicus () Polish astronomer, creator of the heliocentric system of the world. Explained the reasons for the apparent movement of the planets. His book On the Revolutions of the Celestial Spheres was banned by the Catholic Church. However, the discovery of Copernicus was picked up by outstanding scientists and formed the basis of a new natural science. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

Basic concepts: 1.Closed system of bodiesClosed system of bodies 2.Resultant forceResultant force 3.InertiaInertia 4.InertiaInertia 5.Inertial frames of referenceInertial frames of reference 6.Gravitational forcesGravitational forces 7.Gravity forceGravity 8.Free fall accelerationFree fall acceleration 9.Deformation and its typesDeformation and its types 10. Body weightBody weight 11. WeightlessnessWeightlessness 12. Friction force and its types Friction force and its types 13. Force of normal pressure Force of normal pressure > Back to basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: A closed system of bodies is a system in which only internal forces act. To scientists => To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" class="link_thumb"> 9 !} A closed system of bodies is a system in which only internal forces act. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: A closed system of bodies is a system in which only internal forces act. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> title="A closed system of bodies is a system in which only internal forces act. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: The resultant of forces is the geometric (vector) sum of all forces acting on the body. The acceleration of the body is co-directed with the resultant. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>" class="link_thumb"> 10 !} The resultant of forces is the geometric (vector) sum of all forces acting on the body. The acceleration of the body is co-directed with the resultant. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: The resultant of forces is the geometric (vector) sum of all forces acting on the body. The acceleration of the body is co-directed with the resultant. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> title="The resultant of forces is the geometric (vector) sum of all forces acting on the body. The acceleration of the body is co-directed with the resultant. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Inertia is a physical phenomenon, maintaining the speed of a body (even equal to zero) in the absence of interaction with other bodies. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>" class="link_thumb"> 11 !} Inertia is a physical phenomenon, maintaining the speed of a body (even equal to zero) in the absence of interaction with other bodies. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Inertia is a physical phenomenon, maintaining the speed of a body (even equal to zero) in the absence of interaction with other bodies. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> title="Inertia is a physical phenomenon, maintaining the speed of a body (even equal to zero) in the absence of interaction with other bodies. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Inertia is the property of bodies not to immediately change their speed under the influence of an external load. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" class="link_thumb"> 12 !} Inertia is the property of bodies not to immediately change their speed under the action of an external load. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Inertia is the property of bodies not to immediately change their speed under the influence of an external load. To scientists => To the basic concepts => To basic physical quantities => To the basic laws => To the basic formulas =>"> title="Inertia is the property of bodies not to immediately change their speed under the action of an external load. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic phi" title="(!LANG: Inertial frames of reference - frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists => To the basic concepts => To the basic fi" class="link_thumb"> 13 !} Inertial frames of reference - frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic phi"> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts => To the basic phi" title="(!LANG: Inertial frames of reference - frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated."> title="Inertial frames of reference - frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists => To basic concepts => To basic fi"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Bodies with mass are attracted to each other by forces called gravitational forces. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" class="link_thumb"> 14 !} Massive bodies are attracted to each other by forces called gravitational forces. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Bodies with mass are attracted to each other by forces called gravitational forces. To scientists => To the basic concepts => To basic physical quantities => To the basic laws => To the basic formulas =>"> title="Massive bodies are attracted to each other by forces called gravitational forces. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Gravity is the gravitational force with which the Earth attracts bodies. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" class="link_thumb"> 15 !} Gravity is the gravitational force with which the Earth pulls objects towards itself. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: Gravity is the gravitational force with which the Earth attracts bodies. To scientists => To the basic concepts => To basic physical quantities => To the basic laws => To the basic formulas =>"> title="Gravity is the gravitational force with which the Earth pulls objects towards itself. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formula" title="(!LANG: Free fall acceleration is the acceleration with which any body moves in the Earth's gravitational field, if only gravity acts on it To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formula" class="link_thumb"> 16 !} Free fall acceleration is the acceleration with which any body moves in the Earth's gravitational field, if only gravity acts on it. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formula "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts => K basic physical quantities => To the basic laws => To the basic formula" title="(!LANG: Acceleration of free fall - the acceleration with which any body moves in the Earth's gravitational field, if only gravity acts on it. To scientists => K basic concepts => To the basic physical quantities => To the basic laws => To the basic formula"> title="Free fall acceleration is the acceleration with which any body moves in the Earth's gravitational field, if only gravity acts on it. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formula"> !}

Elastic forces arise when bodies are deformed. Deformation - a change in the shape and volume of the body under external influence. Elastic deformation - disappears after the cessation of exposure. Plastic deformation - does not disappear after the cessation of exposure. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas" title="(!LANG: Body weight is the force with which the body, due to its attraction to the Earth, acts on a support or suspension. Point applications: support or suspension To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas" class="link_thumb"> 18 !} Body weight is the force with which the body, due to its attraction to the Earth, acts on a support or suspension. Application point: support or suspension. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts => K basic physical quantities => To the basic laws => To the basic formulas" title="(!LANG: Body weight is the force with which the body, due to its attraction to the Earth, acts on a support or suspension. Application point: support or suspension. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas"> title="Body weight is the force with which the body, due to its attraction to the Earth, acts on a support or suspension. Application point: support or suspension. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas"> !}

To the basic concepts => To the basic physical quantities => To the basic laws" title="(!LANG: Weightlessness is when the body does not act on a support or suspension, and as a result there is no deformation inside the body; in this case, only gravity acts on the body To scientists => To basic concepts => To basic physical quantities => To basic laws" class="link_thumb"> 19 !} Weightlessness is when the body does not act on a support or suspension, and as a result, there is no deformation inside the body; in this case, only the force of gravity acts on the body. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts => To the basic physical quantities => To the main laws" title="(!LANG: Weightlessness is when the body does not act on a support or suspension, and as a result there is no deformation inside the body; in this case, only gravity acts on the body. To scientists => To basic concepts => To basic physical quantities => To the main laws"> title="Weightlessness is when the body does not act on a support or suspension, and as a result, there is no deformation inside the body; in this case, only the force of gravity acts on the body. To scientists => To basic concepts => To basic physical quantities => To basic laws"> !}

Friction force - occurs along the surface of 2 rubbing bodies due to the deformation of these surfaces (compression of irregularities). Nature - electromagnetic Directed along the surface against displacement The static friction force arises if a force acts on the body, tending to move it from its place. Directed against this force Equal in absolute value to this force. It can only increase up to a certain value, after which the body starts to move. The sliding friction force occurs when a force acts on the body, which sets the body in motion. Directed against this force along the surface of the support. Rolling friction occurs when one body rolls over the surface of another. Directed along the rolling surface, against rotation. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: The force of normal pressure is the resultant of all forces acting on the body perpendicular to the plane of motion. To scientists => K basic concepts => To basic physical quantities => To basic laws => To basic formulas =>" class="link_thumb"> 21 !} The force of normal pressure is the resultant of all forces acting on the body along the perpendicular to the plane of motion. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts = > To the basic physical quantities => To the basic laws => To the basic formulas =>" title="(!LANG: The force of normal pressure is the resultant of all forces acting on the body along the perpendicular to the plane of motion. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> title="The force of normal pressure is the resultant of all forces acting on the body along the perpendicular to the plane of motion. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas =>"> !}

Basic physical quantities: 1. ForceForce 2.MassMass 3.AccelerationAcceleration 4.Absolute elongation of the bodyAbsolute elongation of the body 5.Relative elongation of the bodyRelative elongation of the body 6. Mechanical stress Mechanical stress To scientists => To basic concepts => To basic laws => To basic formulas => To the basic concepts => To the basic laws => To the basic formulas =>">

Force (F) is a vector physical quantity that characterizes the action of one body on another, as a result of which the body acquires acceleration or changes shape and size. It is characterized by: magnitude direction point of application Forces (by nature) gravitational nuclear electromagnetic acting at a distance acting by contact external internal To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

To the basic concepts => To the basic physical quantities => To the basic laws " title="(!LANG:Mass: 1) is a scalar physical quantity characterizing the inertia of the body. 2) it is a scalar physical quantity characterizing the gravitational properties of the body. To scientists => To basic concepts => To basic physical quantities => To basic laws" class="link_thumb"> 24 !} Mass: 1) is a scalar physical quantity characterizing the inertia of the body. 2) it is a scalar physical quantity characterizing the gravitational properties of the body. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => [m]=[kg] To the basic concepts => To the basic physical quantities => To the basic laws "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => [m]=[kg]"> To the basic concepts = > To the basic physical quantities => To the basic laws " title="(!LANG: Mass: 1) is a scalar physical quantity characterizing the inertia of the body. 2) it is a scalar physical quantity characterizing the gravitational properties of the body. To scientists => To basic concepts => To basic physical quantities => To basic laws"> title="Mass: 1) is a scalar physical quantity characterizing the inertia of the body. 2) it is a scalar physical quantity characterizing the gravitational properties of the body. To scientists => To basic concepts => To basic physical quantities => To basic laws"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed). Δv" title="(!LANG:To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed) Δv" class="link_thumb"> 25 !} To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed). Δv - change in speed t - time during which this change occurred To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed). Δv"> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed). Δv is the change in speed t is the time during which this change occurred"> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time ( rate of change). Δv" title="(!LANG:To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed) Δv"> title="To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Acceleration (a) is a vector physical quantity showing the change in speed per unit of time (rate of change of speed). Δv"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx = x 2 - x 1 Δx - absolute elongation" title = "(!LANG: The absolute lengthening of the body is the difference between the final and initial length [Δx]=[m] To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx = x 2 - x 1" class="link_thumb"> 26 !} The absolute elongation of the body is the difference between the final and initial length of the body. [Δx]=[m] To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx = x 2 - x 1 Δx – absolute body elongation x1 – initial body length x2 - final body length To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx \u003d x 2 - x 1 Δx - absolute udl "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx \u003d x 2 - x 1 Δx - absolute elongation of the body x1 - the initial length of the body x2 - the final length of the body "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx = x 2 - x 1 Δx – absolute elongation" title="(!LANG: The absolute elongation of the body is the difference between the final and initial length of the body. [Δx]=[m] To scientists => To basic concepts => To basic physical values ​​\u003d\u003e To the basic laws \u003d\u003e To the basic formulas \u003d\u003e Δx = x 2 - x 1 Δx - absolute extension"> title="The absolute elongation of the body is the difference between the final and initial length of the body. [Δx]=[m] To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx = x 2 - x 1"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x" class="link_thumb"> 27 !} Relative elongation of the body (ε) is the ratio of the absolute elongation to the original length of the body. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx – absolute elongation of the body x – initial length of the body"> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx – absolute elongation of the body x " title="(!LANG: Relative elongation of the body (ε) is the ratio of the absolute elongation to the original length of the body To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x"> title="Relative elongation of the body (ε) is the ratio of the absolute elongation to the original length of the body. To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - the force acting on the body S - the area of ​​\u200b\u200bpov To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F is the force acting on the body S is the surface area" class="link_thumb"> 28 !} Mechanical stress is the ratio of force per unit surface area. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F is the force acting on the body S is the surface area "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - the force acting on the body S - the surface area on which the force acts "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - the force acting on body S – surface area" title="(!LANG:Mechanical stress is the ratio of force per unit surface area. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => F is the force acting on the body S is the surface area"> title="Mechanical stress is the ratio of force per unit surface area. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => F - force acting on a body S - surface area"> !}

Basic laws: 1. Newton's first law Newton's first law 2. Newton's second law Newton's second law 3. Newton's third law Newton's third law 4. Law of universal gravitation Law of universal gravitation 5. Hooke's law Hooke's law To scientists => To basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Newton's laws are applicable only in inertial frames of reference. The law of universal gravitation can be applied if: the bodies are material points of the body are homogeneous balls or have a symmetrical distribution of mass relative to the center of the body. Hooke's law is valid only for elastic deformations. To wasps "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Newton's laws are applicable only in inertial reference systems. The law of universal gravitation can be applied if: bodies are material points bodies are homogeneous balls or have a symmetrical distribution of mass relative to the center of the body. Hooke's law is valid only for elastic deformations. Newton's third law Newton's third law 4. Law of universal gravitation Law of universal gravitation 5. Hooke's law Hooke's law To scientists => To OS"> title="Basic laws: 1. Newton's first law Newton's first law 2. Newton's second law Newton's second law 3. Newton's third law Newton's third law 4. Law of universal gravitation Law of universal gravitation 5. Hooke's law Hooke's law To scientists => To wasps"> !}

To the basic concepts => To the basics" title="(!LANG: Newton's first law: There are such frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists = > To the basic concepts => To the main" class="link_thumb"> 30 !} Newton's first law: There are such frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basics "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts => To the basics" title="(!LANG: Newton's first law : There are such frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated."> title="Newton's first law: There are such frames of reference, relative to which the body is at rest or moves uniformly and rectilinearly, if other bodies do not act on it or the actions of other bodies are compensated. To scientists => To basic concepts => To basics"> !}

To the basic concepts " title="(!LANG: Newton's second law: The acceleration received by the body is directly proportional to the resultant of the forces applied to the body, and inversely proportional to the mass of the body. The direction of acceleration coincides with the direction of the resultant. To scientists => To the basic concepts" class="link_thumb"> 31 !} Newton's second law: The acceleration received by a body is directly proportional to the resultant of the forces applied to the body and inversely proportional to the mass of the body. The direction of acceleration coincides with the direction of the resultant. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>"> To the basic concepts " title="(!LANG:Newton's Second Law: The acceleration received by the body is directly proportional resultant of forces applied to the body, and inversely proportional to the mass of the body.The direction of acceleration coincides with the direction of the resultant.To scientists => To basic concepts"> title="Newton's second law: The acceleration received by a body is directly proportional to the resultant of the forces applied to the body and inversely proportional to the mass of the body. The direction of acceleration coincides with the direction of the resultant. To scientists => To basic concepts"> !}

To the basic concepts => To the basic physical quantities => " title="(!LANG: Newton's Third Law: When two bodies interact, a pair of forces always arises, which: 1) are equal in absolute value 2) are opposite in direction 3) lie on one straight line 4) of the same nature To scientists => To basic concepts => To basic physical quantities =>" class="link_thumb"> 32 !} Newton's third law: When two bodies interact, a pair of forces always arises, which are: 1) equal in absolute value 2) opposite in direction 3) lie on the same straight line 4) of the same nature To scientists => To basic concepts => To basic physical quantities => To the basic laws => To the basic formulas => Forces do not compensate each other, as they are applied to different bodies. To the basic concepts => To the basic physical quantities => "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Forces do not compensate each other, as they are applied to different bodies."> K basic concepts => To the basic physical quantities => " title="(!LANG: Newton's Third Law: When two bodies interact, a pair of forces always arises, which: 1) are equal in absolute value 2) are opposite in direction 3) lie on one straight line 4 ) of the same nature To scientists => To basic concepts => To basic physical quantities =>"> title="Newton's third law: When two bodies interact, a pair of forces always arises, which are: 1) equal in absolute value 2) opposite in direction 3) lie on the same straight line 4) of the same nature To scientists => To basic concepts => To basic physical quantities =>"> !}

Law of universal gravitation: All material points are attracted to each other with a force, the modulus of which is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. The forces lie on one straight line connecting the centers of mass of these bodies, and are directed towards each other. Physical meaning The gravitational constant is numerically equal to the force with which two material points with a mass of 1 kg each are attracted at a distance of 1 m. To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

Hooke's law: Brief entry: The elastic force is directly proportional to the displacement of the body and opposite in sign to it. – coefficient of rigidity Δx – absolute elongation of the body (displacement). Full record: The mechanical stress that occurs in the body within the limits of elasticity is directly proportional to the relative stress. or - Young's modulus (numerically equal to mechanical stress at a relative elongation equal to one). To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas =>">

To the basic concepts => To the basic physical quantities => To the basic laws => 1. Absolute body elongationAbsolute body elongation 2. Relative body elongationRelative body elongation 3. Mechanical stress" title="(!LANG:Basic formulas: To scientists => K basic concepts => To the basic physical quantities => To the basic laws => 1. Absolute elongation of the bodyAbsolute elongation of the body 2. Relative elongation of the bodyRelative elongation of the body 3. Mechanical stress" class="link_thumb"> 35 !} Basic formulas: To scientists => To basic concepts => To basic physical quantities => To basic laws => 1. Absolute elongation of the body Absolute elongation of the body 2. Relative elongation of the body Relative elongation of the body 3. Mechanical stress Mechanical stress 4. Friction forces and its types Friction forces and its types 5. GravityGravity To the basic concepts => To the basic physical quantities => To the basic laws => 1. Absolute elongation of the bodyAbsolute elongation of the body 2. Relative elongation of the bodyRelative elongation of the body 3. Mechanical stress "> To the basic concepts => To the basic physical quantities => To the basic laws => 1. Absolute elongation of the body Absolute elongation of the body 2. Relative elongation of the body Relative elongation of the body 3. Mechanical stress Mechanical stress 4. Forces of friction and its types To the basic laws => 1. Absolute body elongationAbsolute body elongation 2. Relative body elongationRelative body elongation 3. Mechanical stress" title="(!LANG: Basic formulas: To scientists => To basic concepts => To basic physical quantities => K basic laws => 1. Absolute body elongationAbsolute body elongation 2. Relative body elongationRelative elongation body 3. Mechanical stress"> title="Basic formulas: To scientists => To basic concepts => To basic physical quantities => To basic laws => 1. Absolute elongation of the bodyAbsolute elongation of the body 2. Relative elongation of the bodyRelative elongation of the body 3. Mechanical stress"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute lengthening of the body x 1 - initial length of the body x 2 - final length of the body" title="(!LANG:Absolute lengthening of the body: Δx \u003d x 2 - x 1 To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute elongation of the body x 1 - initial body length x 2 - final body length" class="link_thumb"> 36 !} Absolute elongation of the body: Δx \u003d x 2 - x 1 To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute body elongation x 1 - initial body length x 2 - final body length To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x 1 - the initial length of the body x 2 - the final length of the body "> To the basic concepts => To the basic physical quantities \u003d > To the basic laws => To the basic formulas => Δx - absolute elongation of the body x 1 - the initial length of the body x 2 - the final length of the body "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas = > Δx – absolute body lengthening x 1 – initial body length x 2 – final body length" title="(!LANG: Absolute body lengthening: Δx = x 2 - x 1 To scientists => To basic concepts => To basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x 1 - initial length of the body x 2 - final length of the body"> title="Absolute elongation of the body: Δx \u003d x 2 - x 1 To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute body elongation x 1 - initial body length x 2 - final body length"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x - the initial length of the body" title="(!LANG: Relative body elongation: To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x - the initial length of the body" class="link_thumb"> 37 !} Relative elongation of the body: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute body elongation x - initial body length To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx - absolute elongation of the body x - the initial length of the body "> To the basic concepts => To the basic physical quantities => To the basic laws => K basic formulas => Δx – absolute lengthening of the body x – initial length of the body"> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => Δx – absolute lengthening of the body x – initial length of the body" title= "(!LANG: Relative elongation of the body: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute body elongation x - initial body length"> title="Relative elongation of the body: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => Δx - absolute body elongation x - initial body length"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F is the force acting on the body S is the surface area on which the force acts" title="(!LANG: Mechanical stress: To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F is the force acting on the body S is the surface area on which the force acts" class="link_thumb"> 38 !} Mechanical stress: To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - force acting on the body S - surface area on which the force acts To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F is the force acting on the body S is the surface area on which the force acts "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - the force acting on the body S - the surface area on which the force acts "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F – force acting on the body S – surface area on which the force acts" title="(!LANG: Mechanical stress: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas = > F is the force acting on the body S is the surface area on which the force acts"> title="Mechanical stress: To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => F - force acting on the body S - surface area on which the force acts"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - reaction force of the support µ 0 - static friction coefficient µ k - coefficient tr" title="(!LANG: Force of static friction Friction force slip Force of rolling friction To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - support reaction force µ 0 - coefficient of static friction µ k - coefficient tr" class="link_thumb"> 39 !} The force of static friction The force of sliding friction The force of rolling friction To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - support reaction force µ 0 - static friction coefficient µ k - coefficient of friction rolling µ - coefficient of sliding friction R - radius To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - the reaction force of the support µ 0 - the coefficient of static friction µ to - the coefficient tr "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - the reaction force of the support µ 0 - the coefficient of static friction µ to - the coefficient of rolling friction µ - the coefficient of sliding friction R - radius "> To the basic concepts => To the basic physical quantities => To the main laws => To the basic formulas => N - support reaction force µ 0 - coefficient of static friction µ k - coefficient tr" title="(!LANG: Force of static friction Force of sliding friction Force of rolling friction To scientists => To basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - support reaction force µ 0 - static friction coefficient µ k - coefficient tr"> title="The force of static friction The force of sliding friction The force of rolling friction To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => N - support reaction force µ 0 - static friction coefficient µ k - coefficient tr"> !}

To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => m - body mass g - free fall acceleration" title="(!LANG: Gravity: To scientists => To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => m - body mass g - free fall acceleration" class="link_thumb"> 40 !} Gravity: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => m - body mass g - free fall acceleration To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => m - body mass g - acceleration of free fall "> To the basic concepts => To the basic physical quantities => To the basic laws => To the basic formulas => m - body mass g - free fall acceleration "> To basic concepts => To basic physical quantities => To basic laws => To basic formulas => m - body mass g - free fall acceleration" title="(! LANG: Force of gravity: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => m - body mass g - free fall acceleration"> title="Gravity: To scientists => To basic concepts => To basic physical quantities => To basic laws => To basic formulas => m - body mass g - free fall acceleration"> !}

Material Point Dynamics

Dynamics. Introduction to dynamics. Laws and axioms of material point dynamics. Basic equation of dynamics. Two main tasks of dynamics. Solution of the inverse problem of dynamics. Examples of solving the inverse problem of dynamics. Rectilinear oscillations of a material point. The condition for the occurrence of fluctuations of a material point. Classification of fluctuations of a material point. Damped oscillations of a material point. Decrement of fluctuations of a material point. Forced vibrations of a material point. Resonance. Relative motion of a material point. Forces of inertia. Dynamics of a mechanical system. mechanical system. - Dynamics.ppt

Body Dynamics

Dynamics. Dynamics is a branch of mechanics that considers the causes of the movement of bodies (material points). What is the basis of dynamics? What are the frames of reference for Newton's laws? Newton's laws are applicable only for inertial frames of reference. Newton's first law states: Frames of reference in which Newton's first law holds are called inertial. Newton's second law. Newton's third law states: - Body dynamics.ppt

Point dynamics

Dynamics of a material point. Dynamics before Newton. Aristotle's teaching. Founding father of physics. What did Aristotle teach? Aristotle's law of dynamics. Galilean dynamics. Book of Galileo. Inertia movement. The law of proportionality of the speed of movement. Newtonian dynamics. Isaac Newton. Biography. The era of the full maturity of the human mind. Newton's laws. Newton's first law. Features of Newton's laws. - Point dynamics.ppt

Newtonian dynamics

Basic concepts and laws of dynamics. Inertia. Newton's first law. Weight. Inertial reference systems. Forces of elasticity. The force of elasticity is directed opposite to the force of gravity. Composition of forces. The principle of superposition. Newton's second law. Newton's third law. Third law. - Dynamics of Newton.ppt

Material Point Dynamics

Dynamics of a material point. Newton's first law. Material point. Speed. Reference system. Effects. Essence of Newton's first law. Mass and momentum of a body. Weight. Body. mathematical expression. Basic equation of dynamics. Change in momentum of the body. Kilogram. The action of bodies on each other. An action produces an equal and opposite reaction. Impulse of an arbitrary system of bodies. The speed of the center of inertia of the system. The basic equation of the dynamics of translational motion. The resultant of all external forces. Expressions in brackets. The rate of change of the momentum of the system. Center of the mechanical system. - Dynamics of a material point.ppt

Movement of bodies on a plane

Physics Preparation for the exam. In search of effective ways to prepare. Mechanics: Movement under the action of several forces. Study of the motion of a body along an inclined plane. Algorithm for solving problems on Newton's laws of dynamics. Read the condition of the problem, highlight the bodies given by the condition. Perform an analysis of the interaction of bodies. Briefly write the problem statement. Make a drawing, depicting interacting bodies on it. Solve in general terms the resulting system of equations with respect to the unknowns. Substitute numerical data in the solution general view, do the calculations. Estimate the obtained values ​​of unknown quantities. - Movement of bodies on a plane.ppt

Movement of a body on an inclined plane

Movement of a body along an inclined plane. The purpose of the lesson. Tasks. Lesson type. Stages of the lesson. Knowledge update. Goal setting. Father and son are skiing down the mountain. Planning. "Discovery" of new knowledge. - The movement of the body on an inclined plane.pptm

Dynamic tasks

Dynamics in tasks. Content. Consider Newton's laws. Let's remember what forces we know. "Varieties" of the force of elasticity. Forces of friction. Plan for solving problems in dynamics. The movement of bodies in horizontal direction. Two bodies of masses 50 g and 100 g are connected by a thread. The railroad car drives two platforms with uniform acceleration. Vertical movement. A body of mass 50 kg is pressed against a vertical wall. Loads with masses of 2 kg and 1 kg. Determine the accelerations of the loads. Movement on an inclined plane. A horizontal force F acts on a bar of mass m. With what acceleration will the loads move. The force will be at its minimum uniform motion. - Tasks on dynamics.pptx

ball throw

Throwing the ball into the court. Will the ball hit. Model development. Formal (mathematical) model. The condition for the ball to hit the court. Computer experiment. Analysis of results. The range of angle values. A body is thrown from a certain height with an initial velocity. Define initial parameters. - Throwing the ball.ppt

Rotation of a rigid body

Rotation of a rigid body. The equation of motion. Types of motion of a rigid body. Rotational motion of a rigid body. Plane motion of a rigid body. Rotation of a rigid body around a fixed axis. Kinetic energy of a rotating rigid body. Flat movement. Properties of the moment of inertia. Theorem on mutually perpendicular axes. Moments of inertia of various bodies. Rolling down an inclined plane. Maxwell disk. free axles. moments of inertia. Gyroscope. The use of gyroscopes. condition for the equilibrium of a rigid body. Rotation of a rigid body. -

slide 1

General lesson in 9th grade

Fundamentals of Dynamics

slide 2

The purpose of the lesson:

repeat and systematize the material on the topic "Fundamentals of Dynamics"; to teach to determine the logical connection between concepts and phenomena; teach how to draw diagrams with the structure of the topic; development oral speech; development of the ability to see physical phenomena in the surrounding processes and be able to explain them.

slide 3

Epigraphs for the lesson:

I did what I could, let others do better. Isaac Newton (1643 - 1727)

slide 4

During the classes Organizing time. Today we have an unusual day. Unusual because we have public lesson. I hope our lesson goes well. And now a little about how our lesson will go today. 2. Introduction. Today we summarize our work on the topic: "Fundamentals of Dynamics". A person not only strives for knowledge, not only receives it, but also systematizes it. Newton created mechanics as an attempt to create a system that explains the world, and he succeeded. The purpose of our lesson will be to systematize knowledge on the topic "Fundamentals of Dynamics". The result of the work will be a diagram with the structure of this topic (Scheme No. 1).

slide 5

Scheme No. 1 "The structure of dynamics."

Dynamics What are you studying?

Description means

Basic concepts Laws of dynamics: Force interactions:

Limits of applicability:

slide 6

What does dynamics study? What means are used to describe dynamics? What are the limits of applicability of the laws of dynamics? We will keep records on the sheets that you have on the tables (Scheme No. 1).

Today we must remember the following questions:

Slide 7

First, let's check how you can count? Listen carefully to the poem and answer my question: HOW MANY PHYSICAL VALUES ARE NAMED IN THIS POEM?

"Physical workout"

Slide 8

A LONE PHYSICIST, SCRATCHING THE CROP, MEASURES LENGTH, MASS AND TIME. A COUPLE OF PHYSICISTS DREAMS TOGETHER MEASURING TEMPERATURE, DENSITY, VOLUME. THREE PHYSICISTS, LINED IN A ROW, CHANGE ENERGY, SPEED, CHARGE. FOUR PHYSICISTS IN A GOOD MOOD MEASURE THE PRESSURE, AND IN A BAD MOOD THE ACCELERATION. FIVE PHYSICISTS RUNNING INTO THE SQUARE, MEASURING THE MOMENTUM, FREQUENCY, FORCE AND AREA, SIX PHYSICISTS COMING TO THE SEVENTH FOR THE NAME DAY, MEASURING ANY PHYSICAL VALUES. (Answer - 15)

Slide 9

What does dynamics study? (Dynamics studies the cause of the change in speed, the cause of acceleration) Who stood at the origins of dynamics? (Isaac Newton)

Slide 10

Let's once again turn the pages of the great discoveries of Isaac Newton (message "Newton's Discoveries").

slide 11

Experience number 1: put a coin on a cardboard lying on a glass. With a snap of a finger, we knock out a cardboard box. The cardboard falls on the table, and the coin falls vertically down into the glass. Explain why the cardboard flies off and the coin falls into the glass? (The phenomenon of inertia)

experimental part

slide 12

(By flicking a finger on the card, we apply force to it. The card moves so fast that it does not have time to drag the clothespin behind it. The clothespin falls down due to gravity, because the card no longer supports it. If we push the card with insufficient force, it will drag the clothespin with it, and gravity will pull the top of the clothespin down, causing it to flip over.)

Experiment number 2: Put a postcard on the glass. Place the clothespin so that it is above the middle of the glass. Flick the card sharply and forcefully with your finger so that it flies to the side. Repeat this several times. Sometimes the clothespin falls into the glass in its original position, and sometimes, falling, it turns over.

slide 13

What are the laws of dynamics? Newton's first law Newton's second law Newton's third law

Laws of dynamics

Slide 14

State Newton's first law. How can this law be written?

There are such frames of reference with respect to which bodies keep their speed unchanged if no other bodies act on them.

slide 15

→ → → → → → Feq. = F+Fresist = 0 V=V0 V = const → → a=0 Fequal=0

→ Fresist. → F → V0 → V

slide 16

State Newton's second law. How can this law be written?

Slide 17

The acceleration of a body is directly proportional to the resultant of the forces applied to it, and inversely proportional to its mass. Where F is the resultant of all forces applied by bodies [N]; a – acceleration [m/s²]; m – mass [kg].

Slide 18

State Newton's third law. How can this law be written?

Slide 19

The forces with which two bodies act on each other are equal in magnitude and opposite in direction.

Slide 20

Force is a quantity that characterizes the interaction of bodies. Let's remember what forces we know. Gravity force, elastic force, friction force, Archimedean force, universal gravitation force, support reaction force, body weight. We write in scheme 1, dividing into two groups.

slide 21

What unites these forces? Why were they distributed in this way? (Gravitational and electromagnetic nature.) Let's remember the formulas for calculating these forces?

slide 23

What initial speed need to inform the arrow by releasing it vertically upwards from the bow so that it falls to the ground after 6 s? What is the maximum height it will reach?

The solution of the problem

slide 24

Given: Solution: t = 6 with h = h0 + V 0 t - (1)

hmax - ? because h0 = h = 0 (since the point of departure and the point of fall of the arrow V 0 - ? are at the same height, taken as the zero level).

Then equation (1) will take the form: 0 = V 0 t -

0 t => V 0 = = (2) V 0 = = 30 m/s h max= h0 + V 0 t - (3)

where t is the time of lifting the boom to maximum height since h0 = 0 (by condition), then V = V0 - gt, where V = 0 (because at the highest point of the ascent, the speed of the arrow is 0), then

V 0 = t =>t = (4) t = = 3s h max = 30 3 – = 45m

Answer: V 0 \u003d 30 m / s, h max \u003d 45 m

Slide 25

When can we apply Newton's laws? Let's turn to experience. Experience 3: (a disk rotating around its axis, balls on threads are fixed on it)

Limits of applicability of Newton's laws

slide 26

What forces act on the balls? (Gravity and elasticity) What will happen if the disk is put into rotation? (The balls will deviate from the vertical position) Why is the result different? (The accelerations of bodies are different) Are Newton's laws fulfilled? Why? (Non-inertial frame of reference.) With what speeds must bodies move in order for Newton's laws to be fulfilled? (Much less than the speed of light.)

Slide 27

Attention. Guys, there's a "winding road" sign ahead. You are bus passengers and must show how the position of the passenger's body relative to the seat of the chair changes, i.e. relative to the Earth in different situations.

Physical education "Bus ride"

Slide 28

The bus slowly pulls away from the stop. The bus brakes hard. Turn left at high speed. Turn right at high speed. The bus slowly pulls away from the stop. The bus brakes hard. Turn left at high speed. Turn right at high speed. The bus moves uniformly and in a straight line.

Slide 29

Option 1 1. The car is moving at a constant speed. Choose the correct statement. A. The acceleration of the car is constant and different from zero. B. The resultant of all forces applied to the car is zero. Q. Only gravity acts on the car. D. Only the reaction force of the support acts on the car.

Control and self-control

slide 30

2. How does a body of mass 0.5 kg move under the action of a force of 2 N? Choose the correct answer. A. With a constant speed of 0.25 m/s. B. With a constant speed of 4 m/s. B. With an acceleration of 4 m/s2. G. With an acceleration of 0.25 m/s2.

3. How would the Moon begin to move if at one moment the gravitational force from the Earth and other cosmic bodies ceased to act on it? Choose the correct answer. A. Uniformly and rectilinearly tangential to the original trajectory of movement. B. Rectilinear towards the Earth. B. Moving away from the Earth along a straight line directed from the center of the Earth. D. Moving away from the Earth in a spiral.

Slide 31

4. The body moves in a circle at a constant speed. Note which of the four statements are correct and which are incorrect. A. The acceleration of the body is zero. B. The resultant of all forces applied to the body is zero. B. The resultant of all forces applied to the body is constant in direction. D. The resultant of all forces applied to the body is constant in absolute value.

slide 32

Option 2

1. The plane flies horizontally in a straight line. The speed of the aircraft increases in direct proportion to time. Choose the correct statement. A. The aircraft moves uniformly and in a straight line. B. The resultant of all forces applied to the aircraft is nonzero. B. The acceleration of the aircraft is zero. D. The resultant of all forces applied to the aircraft increases with time.

slide 2

Dynamics

Dynamics (Greek δύναμις - force) is a section of mechanics that studies the causes of mechanical motion. Dynamics operates with such concepts as mass, force, momentum, energy.

slide 3

Also, dynamics is often called, in relation to other areas of physics (for example, to field theory), that part of the theory under consideration, which is more or less directly analogous to dynamics in mechanics; in kinematics, such theories usually include, for example, relations obtained from transformations of quantities at change of reference system.

slide 4

Inertia

• On the basis of experimental studies of the motion of balls on an inclined plane
• The speed of any body changes only as a result of its interaction with other bodies.
• Inertia is the phenomenon of maintaining the speed of a body in the absence of external influences.

View all slides