Kinetic Energy

---

Whenever objects are in motion (velocity > 0) there is energy produced due to its movement. This energy is called kinetic energy, the energy of movement. And mathematically, kinetic energy is defined as:

K = (1/2)mv²

By inspection, we also notice that kinetic energy is the total momentum or momentum is the rate of change of kinetic energy.

K = int(0, v, mv); p = dK/dv = mv

It is widely known that energy is neither created or destroyed. Mathematically speaking, this simply means that the initial state of energy in a system is equal to its final state.

E_i = E_f

This statement also implies that if a ball slows down, its kinetic energy has been dissipated into some other form however never "gone".

Sample Problem
A ball of mass m hits a smaller ball of mass m/4 at 4 km/s and comes to rest. What is the velocity of the smaller ball?

Your Answer:

Solution