9TH GRADE · MOMENTUM
Momentum and jet propulsion
Body momentum and forces, collisions, rockets and conservation of momentum.
The entire theory of the lesson is collected here; you can read it without an account. In interactive mode, the same theory appears as cards, followed by questions. with checking the answer and task, and progress is saved.
Basic Concepts
Impulse force
The product of the average force and the time of action is equal to the change in the momentum of the body.
Increasing the stopping time reduces the average force for the same change in impulse that airbags use.
Conservation of Momentum
The total momentum of a closed system remains constant during internal interactions.
The law describes the collisions, recoil and jet propulsion of a rocket due to the release of mass.
Body impulse
A vector quantity equal to the product of a body’s mass and its speed.
The direction of the impulse coincides with the speed, so in one-dimensional collisions the signs must be taken into account.
Physical quantities
Body impulse
The product of a body's mass and its speed.
Unit: kilogram-meter per second ·
Impulse force
The product of the average force and the duration of its action.
Unit: kilogram-meter per second ·
Lesson formulas
Body impulse
Momentum is equal to the product of a body's mass and its speed.
Impulse force
An impulse of average force is equal to the change in the momentum of the body.
Conservation of Momentum
The total impulse of a closed system before interaction is equal to the total impulse after.
Related formulas
The same formulas in the reference, with symbols and units.