A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is
A) the applied force.
B) gravity.
C) friction.
D) All of the forces are doing work.

Question

Quizplus · Accepted Answer

Gravity is a vertical force and does not have a component parallel to the direction of motion, so it does not do any work on the box as it moves horizontally.

A Box Is Pushed Across a Rough Horizontal Floor by a Force