Chapter 6, Problem 6.8P

Interpretation Introduction

Interpretation:

The reason for the negative sign assigned to the work done when the system expands is to be determined.

Concept introduction:

Work $\left(w\right)$ is the energy needed to move an object in the opposite direction of the force applied. The work done by the system is negative and the work done on the system is positive. The formula to calculate the work done against an external pressure is,

$w=-P\Delta V$

Here,

$w$ is the work done by the system or on the system.

$P$ is the external pressure.

$\Delta V$ is the change in the volume.