# Lesson Worksheet: Heat Engines Physics

In this worksheet, we will practice calculating the work extracted by heat engines from the transfer of heat from high to low temperature reservoirs.

Q1:

A heat engine has an efficiency of 0.333. The high-temperature reservoir temperature is a constant . What is the low-temperature reservoir temperature in ? Answer to three significant figures.

Q2:

A heat engine has constant reservoir temperatures of 2,000 K and 200 K.

What is the maximum efficiency of the engine? Answer to three significant figures.

The low-temperature reservoir is heated by 452 J. How much work is done by the heat engine? Answer to three significant figures.

Q3:

The changes in the pressure and the volume of a gas in a cylinder with a movable lid are shown in the graph. The cylinder acts as a Carnot heat engine. The diagrams show the gas in four different conditions, each corresponding to that of the gas after one of the changes. Which change corresponds to the gas in condition A?

• AChange I
• BChange IV
• CChange II
• DChange III

Which change corresponds to the gas in condition B?

• AChange IV
• BChange I
• CChange II
• DChange III

Which change corresponds to the gas in condition C?

• AChange III
• BChange I
• CChange II
• DChange IV

Which change corresponds to the gas in condition D?

• AChange I
• BChange III
• CChange IV
• DChange II

Q4:

What is the efficiency of a heat engine if , the temperature difference between its reservoirs, is equal to the absolute temperature of its low-temperature reservoir?