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Question
A force F is applied on a block of mass M. The block is displaced through a distance d in the direction of the force. What is the work done by the force on the block? Does the internal energy change because of this work?
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Solution
If force F is applied on a block of mass M and displacement of block is d, then work done by the force is given by
W = F.d = Fd cos(0°) = Fd
This work done does not change the internal energy of the block as the internal energy does not include the energy due to motion or location of the system as a whole.
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