Chapter 4, Problem 41R

To determine

To explain: The statement which is always true of work.

Explanation of Solution

Introduction:

Work is force through a distance. Energy is the ability to do work.

Work is not always difficult. Use of machines make work easier. Work does not always involve levers or machines. For example: Work done by a human while walking or running does not involve any levers or machines. However, work always involves a transfer of energy. Energy is therefore described as the ability to do work. For example: A person converts chemical potential energy of the muscles to kinetic energy while running. Since force is applied by the muscles to move through a distance, work is also done.

Conclusion:

Work involves a transfer of energy.