Question

Problem 19

Answer 1

Given information

A heavy crate rests on the bed of a flatbed truck. When the truck accelerates, the crate stays fixed on the truck, so it, too, accelerates.

Step-by-step explanation

Step 1.

Initially, the crate is resting so the force due to gravity and normal force balances each other and there will be no vertical acceleration and that’s why we only look towards the horizontal direction. So, when the truck accelerates the crate is too accelerating i.e. there is a horizontal force applied to the system and due to this force, the friction force is also exerted. This frictional force permits to keep the crate on the bed of the flatbed truck so there is an equal and opposite force to accelerate the crate with the truck due to Newton’s third law of motion.