Physics Help? C4:7

Question

A heavy box rests on the bed of a flatbed truck. When the truck accelerates, the crate remains where it is on the truck. Therefore, the crate and the truck have the same acceleration.

7) a) Draw a free-body diagram of the accelerating truck (not the box). Label all the forces. b) Identify the following for each force on the diagram of the truck: i. the name ii. what the force acts on iii. what exerts the force Silly sample answer: “F1 is the magnetic force acting on the muskrat exerted by hamburger”

Answer 1

(7)

The crate is placed on the flatbed truck.

The truck accelerates and the crate remains on the position.

Explanation :

The crate is at rest with respect to the truck means there is no relative speed between them.

Both the truck and crate are moving with the same acceleration.

If there is no friction at all , as the truck moves towards east, the crate slides towards west.

But there is no external matter except the truck to make the crate move with some acceleration.

It follows that the truck must exert some force on the crate pulling it along with it.

Thus the frictional force acting on the crate keeps the crate on its position.

Free body diagram :

Here the truck accelerates in east direction.

denotes the frictional force.

denotes the accerlerating force.

is the force due to gravity acting downward.

is the normal force.