Bennett Mechanical Test Thermodynamics and Heat 4

Question 1

A car radiator uses circulating coolant to remove engine heat. This is primarily an example of:

Accepted Answer

Convection

Answer

Moving coolant carries heat away from the engine, which is convection.

Question 2

Why are cooking pot handles often made of plastic or wood instead of metal?

Accepted Answer

They are poor conductors and stay cooler

Answer

Plastic and wood insulate, preventing heat from reaching your hand.

Question 3

If you add the same amount of heat to equal masses of water and iron, which heats up to a higher temperature?

Accepted Answer

Iron, because it has a lower specific heat

Answer

Iron's lower specific heat means less energy is needed to raise its temperature.

Question 4

Steam can cause worse burns than boiling water at the same temperature because:

Accepted Answer

Steam releases extra latent heat when it condenses on skin

Answer

Condensing steam releases its latent heat of vaporization onto the skin, adding energy.

Question 5

A bimetallic strip in a thermostat bends when heated because:

Accepted Answer

The two metals expand by different amounts

Answer

Different expansion rates of the bonded metals make the strip curve, triggering the switch.

Bennett Mechanical Test Practice Test