Chapter 5, Problem 1Q

A heavy crate rests on the bed of a flatbed truck. When the truck accelerates, the crate remains where it is on the truck, so it, too, accelerates. What force causes the crate to accelerate?

To determine

The force which causes the crate to accelerate.

Answer to Problem 1Q

The force which causes the crate to accelerate is the static friction between the crate and the truck bed.

Explanation of Solution

The force which exists between the two surfaces in contact is the frictional force. There are two kinds of frictional force namely: static friction and kinetic friction. Static friction arises when the two surfaces in contact are in rest and kinetic friction arises when there is a relative motion between the two surfaces.

In the given situation, the crate was resting on the bed of the flatbed truck. There is force of static friction between the crate and the truck bed. When the truck accelerates this force accelerates the crate also.

Conclusion:

Thus, the force which causes the crate to accelerate is the static friction between the crate and the truck bed.