Chapter 6: Controlling Heat Transfer

Two identical jars are kept in a refrigerator. Jar A contains 250 mL of milk. Jar B

contains 500 mL of milk. The jars are taken out of the refrigerator at the same time.

Which jar will warm to room temperature first?

• Jar A

• Jar B

• Both jars will warm to room temperature at the same time.

• Neither jar will ever warm to room temperature.

Which reason best explains why sand is very hot on a

hot day and water is cool?

• There is less sand than water, so it heats up quicker.

• Sand has a higher specific heat capacity than water.

• Water takes more energy to heat up than sand.

• The sand is initially warmer.

Which type of heat transfer does fiberglass insulation in a dishwasher mainly stop?

• conduction

• convection

• radiation

• reflection

Which of the following substances would require the least

amount of heat to raise its temperature by 20°C?

• 400 g of motor oil

• 400 g of water

• 400 g of soil

• 400 g of iron

Mice generally stay warm under the snow in winter because

• the ground does not freeze under the snow

• the ground has a high specific heat capacity

• snow is a good insulator

• snow is a poor insulator

Why do wood shavings insulate better than solid wood?

• Wood shavings absorb moisture and, therefore, have a

  higher specific heat capacity.

• Wood shavings have dead-air spaces that reduce heat transfer.

• Solid wood has a higher specific heat capacity.

• Wood shavings are lighter than wood.

Which insulation would best keep a house warm in winter?

• 25 mm of fiberglass with an R-value of 4.25

• 50 mm of wood shavings with an R-value of 4.84

• 25 mm of rigid urethane foam with an R-value of 7.50

• 25 mm of air space with a reflective surface with an R-value of 5.54

Keeping warm on a cold day is best done by

• drinking hot liquids

• continuously moving

• wearing a heavy coat

• wearing several layers of clothing

The reason an ocean diver’s suit has a hood is

• to keep the diver’s hair dry

• to make the suit more attractive

• to prevent heat loss from the head

• so the diver does not get water in his/her ears

Diver’s suits are made of

• neoprene with natural rubber mixed in

• two layers of neoprene with nitrogen gas between

• neoprene with bubbles of oxygen trapped in the fabric

• neoprene with bubbles of nitrogen trapped in the fabric