Newton’s second law of motion:
In all interactions or collisions,
Newton’s first law of motion:
In an inelastic collision, kinetic energy is not conserved.
Kinetic energy is conserved in a perfectly elastic collision;
Newton’s third law of motion:
momentum and total energy are conserved.
When two bodies interact, the forces they exert on each other are equal and opposite.
The resultant force acting on a body is equal to the rate of change of its momentum.
It is transferred into other forms of energy (such as heat or sound). Most collisions are inelastic.
An object will remain at rest or keep travelling at constant velocity unless it is acted on by a resultant force.
relative speed is unchanged in a perfectly elastic collision.