Thermodynamics: Why No Engine Can Waste Nothing
A tour of energy, heat and entropy, from pressure cookers and jet engines to heat pumps and sweating glasses.
Thermodynamics · 50 questions
Try 3 questions
1. You cut a uniform steel block in half. Which property is the same in each half as in the whole block?
- Density
- Mass
- Internal energy
Show the answer
Answer: Density
Density is intensive: it does not depend on how much material you have, while mass and internal energy are extensive and halve.
2. What does the zeroth law of thermodynamics make possible?
- Converting all of a fuel's heat into work
- Reaching absolute zero in a lab
- Comparing temperatures with a thermometer
Show the answer
Answer: Comparing temperatures with a thermometer
It states that two bodies each in thermal equilibrium with a third are in equilibrium with each other, which is exactly what lets a thermometer work.
3. A sealed rigid container of gas is warmed from 10 °C to 20 °C. Roughly how much does its pressure rise?
- By about 50 percent
- By about 3.5 percent
- It doubles
Show the answer
Answer: By about 3.5 percent
Pressure scales with absolute temperature: 293 K / 283 K is only about 1.035, so doubling the Celsius number barely changes it.
The whole quiz comes before your apps
BrainTok asks a few questions like these before the apps you choose open, so your screen time turns into learning. For iPhone.
Join the beta