Question

A hammer is used to drive a nail into a board. Work is done in the act of driving the nail. Compared to the moment before the hammer strikes the nail, the mechanical energy of the hammer after its impact will be:

A. Greater, because the hammer has done work.
B. Greater, because work has been done on the hammer.
C. Less, because the hammer has done work.
D. Less, because work has been done on the hammer.

Answer 1

Less, because the hammer has done work

Step-by-step explanation:

The work done by the hammer on the nail is positive. Hammer gives enough energy to nail to move in the wood. To move the nail, hammer has to do some work. Thus some part of the kinetic energy of the hammer is lost. Mechanical energy of the hammer will be less after the impact on nail.