Boxes A and B are in contact on a horizontal, frictionless surface. Box A has mass 21.0 kg and box B has mass 8.0 kg . A horizontal force of 100N is exerted on box A. What is the magnitude of the force that box A exerts on box B?

32N

100N

To understand how box A exerts a force on box B, we can use Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. Therefore, the force that box A exerts on box B will be equal in magnitude but opposite in direction to the force that box B exerts on box A.

In this case, a horizontal force of 100 N is exerted on box A. Since both boxes are in contact with each other and there is no friction, this force will be transmitted from box A to box B.

First, let's calculate the acceleration of box A using the formula F = ma, where F is the force exerted on box A and m is its mass.

F = ma
100 N = 21.0 kg * a
a = 100 N / 21.0 kg
a ≈ 4.76 m/s²

Now, let's calculate the force exerted by box A on box B. This force can be determined using Newton's second law of motion, which states that force (F) is equal to the mass (m) of an object multiplied by its acceleration (a).

F = ma
F = 8.0 kg * 4.76 m/s²
F ≈ 38.08 N

Therefore, the magnitude of the force that box A exerts on box B is approximately 38.08 N.