A secret agent is locked in a room. He pushes against the door but cannot open it. Finally, he falls to the floor exhausted. Has he done any work in the door? Why or why not?

There is not work done at the door because the door did not move.

Explanation:  Work is defined as the movement done by a force.

So if you move to apply a force F in an object and you move it a distance D, the work applied on the object is  

W = F*D

In this case, the secret agent pushes against the door, so there is a force, but the agent does not move the door, so D = 0, so there is no motion of the door, which implies that there is no work done at the door.

true

explanation:

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