I did. You quoted the answer. This is not complicated. You multiply force by distance to get the work done by a force. If you want the work done by two forces you compute the work for each separately and then add.You can't answer the questions I asked in Post #24?
Okay. And the work done by the hand on the block is +10 J. This means that the internal energy of the block-table system increases by 10 J. According to the 1st Law of Thermodynamics, this makes sense. 10 J of energy is put into the system by the hand, and the internal energy of the system increases by 10 J. That explains where the energy went.It means that the net of the work done by block on table and of table on block comes to -10J.
You just apply the definition of work to both bodies (A, B) and the two equal but opposite friction forces acting on them.Note that if one insists that the friction force does work,
For kinetic friction the work done by A on B is of different magnitude than the work done by B on A. That difference represents the energy dissipated as heat.it is not possible to explain where the energy is going.