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 metal spoon and a wooden spoon are left in the same hot soup. Why does the metal spoon feel hotter to the touch sooner?
Answer: Metal conducts heat faster than wood
Metals are good thermal conductors, so heat travels through them quickly to your hand.
What happens to most metals when they are heated?
Answer: They expand
Heating causes the particles in most metals to move more and the material to expand.
Heat moving through empty space from the Sun to Earth is an example of which method of heat transfer?
Answer: Radiation
Radiation transfers heat as electromagnetic waves and needs no medium.
Why does warm air rise above a heater?
Answer: Warm air is less dense than cool air
Heated air expands, becomes less dense, and is pushed up by surrounding cooler air.
Which surface color absorbs the most radiant heat?
Answer: Black
Dark, dull surfaces absorb the most radiant heat while light, shiny ones reflect it.
A bridge has gaps called expansion joints. What is their main purpose?
Answer: To allow for thermal expansion and contraction
Expansion joints give the structure room to expand in heat and contract in cold without cracking.
In which state of matter do particles have the most thermal energy and freedom of movement?
Answer: Gas
Gas particles move fastest and farthest apart, carrying the most thermal energy.