The laws of thermodynamics and heat engines
Grade 11 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
A toy Stirling engine takes in 500 J of heat and gives 420 J of heat to its cold side. How much work does it do, Ari?
A model heat engine takes in 250 J of heat and gives 190 J of heat to its cold side. How much work does it do, Esme?
In the energy bar chart, how much work does the engine do, Jun?
- 1000 J
- 750 J, the bigger output bar
- 250 J
In the energy bar chart, how much heat goes to the cold side, Kira?
Use the picture in question 3.
- 750 J
- 0 J, since good engines waste nothing
- 250 J
In the energy bar chart, what is the engine's efficiency, Luz?
Use the picture in question 3.
- 75%
- 25%
- 400%
Which law says that, by itself, heat flows from hot to cold and not the other way, Noah?
- The second law of thermodynamics
- The first law of thermodynamics
- Newton's third law of motion
Why can't a heat engine turn all of its heat into work, Pia?
- Some heat must flow out to the cold side
- Energy is destroyed inside the engine
- Work and heat use different units
A toy Stirling engine sits on a cup of hot water. Why does it slow down as the water cools, Ren?
- The water's mass drops
- The temperature difference shrinks
- Its fuel tank slowly runs low as it works
When does a toy Stirling engine on a cup of hot water stop for good, Tala?
- When the water reaches room temperature
- When the water reaches 50 °C
- After exactly one minute
A toy Stirling engine can also run on a cup of ice water. Why, Zee?
- Ice water holds more energy than the room
- There is still a temperature difference
- Ice gives off cold energy