A box is moved 20 m across a smooth floor by a force making a downward angle with the floor, so that there is effectively a 10 N force acting parallel to the floor in the direction of motion and a 5 N force acting perpendicular to the floor. The work done is
A) 300 J.
B) 200 J.
C) 100 J.
D) 20 J.
E) 5.0 J.

Question

Quizplus · Accepted Answer

The work done is equal to the force parallel to the direction of motion multiplied by the distance moved. The force parallel to the floor is 10 N, and the distance moved is 20 m, so the work done is 10 N x 20 m = 200 J. The perpendicular force does not do any work as it is acting perpendicular to the direction of motion.

A Box Is Moved 20 M Across a Smooth Floor