Answer:
There are 3 forces exerted on Block B.
Normal force from the floor. This force is perpendicular to the surface of the floor.
Force of friction from the floor. This force opposes the motion of the block.
Force exerted by Block A. This force is exerted by Block A on Block B.
The magnitude of the normal force is equal to the weight of the block, which is 30 N. The magnitude of the force of friction is equal to the coefficient of friction between the block and the floor multiplied by the normal force. The coefficient of friction is typically between 0 and 1, so the magnitude of the force of friction is less than or equal to 30 N. The magnitude of the force exerted by Block A is equal to the magnitude of the force applied to Block A, which is 18 N.
Therefore, there are 3 forces exerted on Block B: the normal force, the force of friction, and the force exerted by Block A.
Step-by-step explanation: