Heat Transfer Evaluation

You pick up a can of soda off of the countertop. The countertop underneath the can feels colder than the rest of the counter. Which explanation do you think is the best?

• The cold has been transferred from the soda to the counter.

• There is no heat energy left in the counter beneath the can.

• Some heat has been transferred from the counter to the soda.

• The heat beneath the can moves away into other parts of the countertop.

After cooking an egg in boiling water, you cool the egg by putting it into a bowl of cold water. Which of the following explains the egg’s cooling process?

• Temperature is transferred from the egg to the water.

• Cold moves from the water into the egg.

• Energy is transferred from the water to the egg.

• Energy is transferred from the egg to the water.

Why do we wear sweaters in cold weather?

• To keep cold out.

• To generate heat.

• To reduce heat loss.

• All of the above.

Amy wraps her dolls in blankets but can’t understand why they don’t warm up. Why don’t they warm up?

• The blankets she uses are probably poor insulators.

• The blankets she uses are probably poor conductors.

• The dolls are made of materials that don’t hold heat well.

• None of the above.

As water in a freezer turns into ice,

• the water absorbs energy from the air in the freezer.

• the water absorbs the coldness from the air in the freezer.

• the freezer air absorbs heat from the water.

• the water neither absorbs nor releases energy.

On a warm sunny day, you will feel cooler wearing light colored clothes because they

• reflect more radiation.

• prevent sweating.

• are not as heavy as dark clothes.

• let more air in.

If you put a metal spoon and a wooden spoon into a pot of boiling water, one will become too hot to touch. Why?

• Metals conduct heat better than wood.

• Wood conducts heat better than metals.

• Metals pull in heat because heat is attracted to metals.

• Wood isn’t as strong as metals.

On a sunny day, the upstairs rooms in a house are usually hotter than the downstairs rooms. Why?

• Cool air is less dense than hot air.

• Warm air rises and cool air sinks.

• The upstairs rooms are closer to the sun.

• Heat rises.

You have a can of soda in your lunchbox that you want to keep cold. Which material will work best to keep it cold and why?

• Aluminum foil wrapped around the soda because metals transfer heat energy easily.

• A paper towel wrapped around the soda because paper soaks up the moisture.

• Wax paper wrapped around the soda because wax paper traps the moisture.

• Your wool sweater wrapped around the soda because wool traps air.

When you hold a metal coat hanger in a camp fire to roast a marshmallow, the coat hanger might get too hot to hold. Why might the coat hanger get too hot?

• The heat radiates along the coat hanger.

• The heat builds up near the flame until it can’t hold it anymore and then moves along the coat hanger.

• Metal atoms vibrate with more energy when they get hot, and they collide with atoms near them, which makes the neighboring atoms vibrate too.

• Since metals melt in fire, they react very strongly to fire and get hot easily.