Chapter 3, Problem 37A

When a junked car is crushed into a compact cube, does its mass change? Its volume? Its weight?

To determine

Whether the mass, volume, and weight change when a junked car is crushed into a compact tube.

Answer to Problem 37A

The mass and weight remain unchanged.

The volume is reduced.

Explanation of Solution

Introduction:

Mass is the property of a physical body and a measure of its resistance to acceleration. Also, it is the total material contained in an object. It is expressed in kilograms.

Volume is the amount of space at that a substance occupies. It is expressed in ${\text{m}}^3$ .

Weight is the force of gravity on an object. The mass and weight are not the same, they are directly proportional to each other.

The expression for weight is as follows:

  $W=mg$

Here, $m$ is the mass and $g$ is the acceleration due to gravity.

Calculation:

If a junked car is crumpled into a compact cube, the mass of the car doesn’t change because the car has all the same parts even after being crushed into a compact cube.

Hence, the mass remains unchanged.

When a junked car is crumpled into a compact cube, the volume of the car has been changed. Because, after crushing into a compact cube, the space within the car has decreases. So the volume of the car decreased.

Hence, the volume is changed.

If a junked car is crushed into a compact cube, the weight of the car doesn’t change. It is the measure of gravity acting on mass. The mass of the car doesn’t change. So the weight of the car remains constant.

Hence, the weight remains unchanged.

Conclusion:

Thus, the mass and weight remain unchanged but the volume is reduced.