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
Water boils at a lower temperature on top of a high mountain because:
Answer: Air pressure is lower at high altitude
Lower atmospheric pressure lets water boil at a temperature below 212°F.
A thermos keeps drinks hot mainly by reducing which type of heat transfer with its vacuum layer?
Answer: Conduction and convection
The vacuum between walls blocks conduction and convection because there is no matter to carry heat.
What is the change of a substance directly from solid to gas without becoming liquid called?
Answer: Sublimation
Sublimation is the direct solid-to-gas transition, as seen with dry ice.
Two identical pots of water are heated, one covered with a lid. Which boils faster?
Answer: The covered pot
A lid traps heat and reduces heat loss by evaporation, so the covered pot boils faster.
Which material would make the best insulator to keep a house warm?
Answer: Fiberglass batting
Fiberglass traps air pockets that slow heat transfer, making it a good insulator.
When you rub your hands together quickly, they get warm because:
Answer: Friction converts mechanical energy into heat
Friction between surfaces transforms motion into thermal energy.
Heat always flows naturally from:
Answer: A hotter object to a cooler object
Heat spontaneously moves from high temperature to low temperature until equilibrium.