Why has no work being done if there is no displacement? use the equation w=fx d to explain your answer

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

A10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. which one has the greater buoyant force on it? explain. b - the aluminum a) both have the same buoyant force. b) the aluminum c) the lead d) it cannot be determined without knowing their volumes.

I’ve been stuck on this for a while