Chapter U3.58, Problem 1E

Interpretation Introduction

Interpretation: Comprehend the use of scale to measure the pressure of the gas in a syringe.

Concept Introduction:

Due to random movement of gas particles, they colloid with other gas particles and also colloid with wall of container. The collision between gas particles of air and wall of container exert pressure on the wall of container.

Explanation of Solution

Syringe is worked on pressure-volume relationship as it is sealed off and volume will remain constant.

As the plunger is pushed inside, the pressure of gas increases. As the pressure increases, the molecules come closer to each other that results the increase in collision number. Overall with increase in pressure, the volume decreases.

The change in pressure can be measured with scale because as the plunger moves inside, the pressure increases and the weight on the scale increases. Thus the measured weight is used to scale the pressure.

  $\text{Pressure = }\frac{\text{measured weight}}{\text{surface area of plunger}}{\text{= lb/in}}^{\text{2}}$