Question

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?​

Answer 1

An object with mass 'm' moving with velocity 'V' has kinetic energy of  21mv2 .

In order to bring it to rest, its velocity has to be reduced to zero, and in order to

accomplish that, the kinetic energy has to be drained off and sent somewhere else.

An external force has to absorb energy from the object, i.e. do negative work on it,

equal to its kinetic energy,or

1/2mv2.

Answer 2

Explanation:

In order to bring it to rest, its velocity has to be decreased to zero, and in order to achieve that, the kinetic energy has to be drained off and sent somewhere else. An external force has to absorb energy from the object, i.e. do negative work on it, equal to its kinetic energy, or -1/2 mv2.