Question

give an example of an object that is at rest but not in equilibrium

Answer 1

Object is at rest. Therefore it's velocity is zero
Object is not in equilibrium. This is equivalent to saying "The net force on the object is not zero".
Thus we are looking for an object that in a particular moment is not moving but it will be moving in the next. This is true for the vertical thrown ball that is reverting its velocity due to gravity but we can think of a lot of other examples, e.g. a resting box that is pulled with a string and just overcoming the static friction or an object that you are holding in your hands and let loose.

Answer 2

Answer:

Explanation:

A =Cork

B=Water

C=Iron

D=Brass

E=Merxury