Question

A chair is pushed across the floor at a constant speed. Draw a free-body diagram clearly showing all the forces applied to the block; compare their magnitudes and directions. Which of the following statements is correct? A) The gravitational force on the block is greater than the applied force. B) The applied force and the gravitational force on the block are equal in magnitude. C) The applied force and the normal force on the block are equal in magnitude. D) The frictional force on the block is greater than the net force.

Answer 1

The free-body diagram clearly showing all the forces applied to the block is attached.

The correct statement is that the applied force and the normal force on the block are equal in magnitude.

Option C is correct

The normal force is perpendicular to the surface, acting upwards. Its magnitude is equal to the gravitational force to prevent the chair from sinking into the floor.

The frictional force acts in the direction opposite to the motion, opposing the applied force. Its magnitude is equal to the applied force in order to maintain a constant speed.

Based on the magnitude and direction comparison, the correct statement is that the applied force and the normal force on the block are equal in magnitude.

The applied force must overcome friction to maintain constant motion, and the normal force counteracts gravity to prevent the chair from sinking into the floor. Both forces act perpendicular to each other, making their magnitudes equal.