## Tuesday, December 22, 2015

### Kinetic Energy and Momentum Relation

Kinetic energy can also be expressed in terms of momentum. Kinetic energy is the energy possessed by a body by virtue of its motion. Kinetic energy can be rearranged in terms of momentum and product of velocity and a half. We can further multiply the equation of mass.

So we can find the relation between kinetic energy and momentum mathematically as shown in the video lesson below.

This can further lead to the law of conservation of linear momentum. If no external force is acting on a system, then the momentum of the system remains constant.

This can be derived basing on the definition of force. We can define force as rate of change of momentum. If no external force is acting, rate of change of momentum is equal to zero. Hence the change in the momentum is equal to zero and hence the momentum is constant.

When a gun is fired from a bullet, there is no external force acting on the system. If bullet is moving in the forward direction and the gun to compensate momentum and conservation, gun moves in back ward direction.

The momentum of gun is equal to bullet and in the opposite direction. By knowing the velocity of the bullet, we can measure the velocity of  gun.