A box is pushed eastward across a rough horizontal floor by a force acting parallel to the floor. A force providing an impulse directed westward on the body is
A) gravity.
B) the applied force.
C) friction.
D) normal reaction force of floor upward on body.
E) a fictitious force.

Question

Quizplus · Accepted Answer

The only force acting opposite to the direction of motion is friction. Therefore, the force providing an impulse directed westward on the body must be friction.

A Box Is Pushed Eastward Across a Rough Horizontal Floor