A boy sits in a tire that is attached to a rope that passes over a pulley fastened to the ceiling and then passes back down to the boy's hands.The weight of the boy plus the tire is W.The force with which the boy must pull on the free end of the rope to support his weight in the tire is
A)(1/2)W
B)W
C)2W
D)(2/3)W
E)(3/2)W

Question

Quizplus · Accepted Answer

When the boy pulls on the rope, he creates a tension that is equal throughout the rope. Since there are two segments of the rope supporting his weight (one segment from the pulley to his hands, and the other from the pulley to the tire), the force he needs to apply is half his weight, or (1/2)W, to balance the forces.

A Boy Sits in a Tire That Is Attached to a Rope