# Newton's First law: Barrier on large transport trucks

## Homework Statement

Explain why large transport trucks have a hard steel barrier between the load and the driver's cab. Consider Newton's first law in your answer.

## Homework Equations

no equations required.

## The Attempt at a Solution

According to Newton’s first law, if no net force acts on an object, it maintains it state of rest or its constant speed in a straight line. The hard steel barrier between the load and the driver’s cab is there to protect the driver from injury. If there was no barrier and the cab stopped abruptly, the load would continue to move in a straight line at its original speed, and collide with the cab. There is no external force to alter the speed or direction of the load, so it will continue moving forward. Therefore it is important to have a hard steel barrier between the load and the driver’s cab to stop it from moving in a straight line and hitting the cab.

Is this correct?

That is correct.

As a footnote: That steel barrier is also called a headache rack.

Ok thanks for the help and the footnote : )

According to Newton’s first law, if no net force acts on an object, it maintains it state of rest or its constant speed in a straight line. The hard steel barrier between the load and the driver’s cab is there to protect the driver from injury. If there was no barrier and the cab stopped abruptly, the load would continue to move in a straight line at its original speed, and collide with the cab. There is no external force to alter the speed or direction of the load, so it will continue moving forward. Therefore it is important to have a hard steel barrier between the load and the driver’s cab to stop it from moving in a straight line and hitting the cab.

Is this correct?

i think you are correct; you could have added a force of friction between the load and the truck's base which may reduce the velocity of the load in forward direction.

SammyS
Staff Emeritus