Thermodynamics and Heat Flashcards
7 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Thermodynamics and Heat flashcards as text
A car radiator uses circulating coolant to remove engine heat. This is primarily an example of:
Answer: Convection
Moving coolant carries heat away from the engine, which is convection.
Why are cooking pot handles often made of plastic or wood instead of metal?
Answer: They are poor conductors and stay cooler
Plastic and wood insulate, preventing heat from reaching your hand.
If you add the same amount of heat to equal masses of water and iron, which heats up to a higher temperature?
Answer: Iron, because it has a lower specific heat
Iron's lower specific heat means less energy is needed to raise its temperature.
Steam can cause worse burns than boiling water at the same temperature because:
Answer: Steam releases extra latent heat when it condenses on skin
Condensing steam releases its latent heat of vaporization onto the skin, adding energy.
A bimetallic strip in a thermostat bends when heated because:
Answer: The two metals expand by different amounts
Different expansion rates of the bonded metals make the strip curve, triggering the switch.
Sweating cools the body mainly through:
Answer: Evaporation absorbing heat from the skin
Evaporating sweat absorbs heat from the body, lowering skin temperature.
At what temperature does pure water freeze at standard atmospheric pressure?
Answer: 32°F (0°C)
Water freezes at 32°F, or 0°C, at standard pressure.