Q. 63

Expert-verified
Found in: Page 598

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# The heat engine shown in FIGURE P uses of a diatomic gas as the working substance.a. Determine , and -b. Make a table that shows , and for each of the three processes.c. What is the engine's thermal efficiency?

a. Temperatures are ,,.

b. Table is,

c. Thermal efficiency is .

See the step by step solution

## Step 1: Calculation for temperature (part a)

a.

The ideal gas law,

The temperature at the second state is,

So,

Because the pressure remains constant, the increase in temperature at state third will be equal to the increase in volume, as shown in the first expression. That is to say,

## Step 2: Table for processes (part b)

b.

In process , heat exchange is nil, whereas work done on the gas is equal to the change in internal energy, which is

.

The work done on the gas in process will be.

The work done by the gas in process will be zero, but the heat released will be equal to the drop in internal energy, which will be .

Table is,

## Step 3: Calculation for thermal efficiency (part c)

c.

The total net work done per cycle is

The heat is .

The thermal efficiency is,