# An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?

We know that, $$E_k \ = \ \frac{mv^2}{2}$$
$$\therefore$$ Work done = change in kinetic energy = $$\frac{mv^2}{2} - 0$$ = $$\frac{mv^2}{2}$$