Question

Two boxes, A and B, are at rest. Box A is on level ground, while box B rests on an inclined plane tilted at angle θ with the horizontal.

(a) Write expressions for the normal force acting on each block.
(b) Compare the two forces; that is, tell which one is larger or whether they are equal in magnitude.
(c) If the angle of incline is 10°, which force is greater?

Answer 1

The normal forces on boxes A and B are equal in magnitude.

Step-by-step explanation:

The normal force is the force exerted by a surface to support the weight of an object resting on it. For box A on level ground, the normal force is equal in magnitude and opposite in direction to the weight of the box. So, the expression for the normal force on box A is NA = mg.

For box B on an inclined plane, the normal force is still equal in magnitude and opposite in direction to the weight of the box. So, the expression for the normal force on box B is also NB = mg.

Since both boxes are at rest, the normal forces for both boxes are equal in magnitude. Therefore, NA = NB.