Each atom in the ideal crystalline solid experiences the same potential due to the other atoms in the material. The binding energy of the atom in the solid is the depth of the potential well at its ...

You must have energy to do work. You do not have to do work if you have energy though - potential energy does not do work. Specifically, in the example above, a person could not push the box (and ...

When work is done energy is transferred to the object and it gains gravitational potential energy. If the object falls from that height, the same amount of work would have to be done by the force ...