Answer:
C) a book that has no net force acting on it and is sitting on a table
Explanation:
Equilibrium means the situation in which net force on a system is zero and hence the acceleration must be zero
this equilibrium is of two types
(1) Static equilibrium
Here object has net force zero and it remains at rest position
(2) Dynamic equilibrium
Here object has net force zero and object is moving at constant velocity
So here for static equilibrium condition we need to find the situation when net force is zero as well as the object must be a rest, so correct answer will be given as
C) a book that has no net force acting on it and is sitting on a table
