Question

suppose that the acceleration of an object is zero. Does this mean that there is no force acting on it?

Answer 1

There could be a force on all sides pushing at the same speed to make it not move hypothetically, but in generic terms in most circumstances yes

Answer 2

not necessarily. It could mean that the forces acting on the object are balances and that the net force of the object is 0.

Step-by-step explanation:

An example would be if you get a book on the table. It doesn't move; however, the force of gravity pulls downwards onto it while the normal force of the table will try to push up on it. These forces will be equal but opposite and are balanced.