Answer: Balanced Force
Step-by-step explanation:
The rock is not moving, this means that the rock is not accelerated.
By the second Newton's law, we know that:
Force equals mass times acceleration.
Then if we do not have acceleration, means that the net force is equal to zero.
This happens when we have balanced forces, meaning that the normal force that does the rock when the man pushes it, is equal in magnitude but in opposite direction, so the net force is equal to zero.
