Heat Transfer

Front

Why does the spoon get hot when stirring hot chocolate?

Back

Conduction

Answer explanation

The spoon gets hot due to conduction, which is the transfer of heat through direct contact. As the spoon stirs the hot chocolate, heat moves from the liquid to the spoon, making it hot.

Front

The sun warms your skin on a cold day.

Back

Radiation

Answer explanation

The sun warms your skin through radiation, which is the transfer of heat in the form of electromagnetic waves. Unlike conduction and convection, radiation does not require a medium to transfer heat.

Front

Macaroni rises and falls in a pot of heated water.

Back

Convection

Answer explanation

Macaroni rises and falls due to convection, where hot water rises and cooler water sinks, creating a circular motion that moves the pasta. This process is driven by temperature differences in the water.

Front

You burn your hand by touching a hot stove.

Back

Conduction

Answer explanation

You burn your hand by touching a hot stove due to conduction, which is the transfer of heat through direct contact. The heat from the stove is transferred to your skin, causing the burn.

Front

Warming your feet in front of a fire.

Back

Radiation

Answer explanation

Warming your feet in front of a fire primarily occurs through radiation, as heat is transferred from the fire to your feet without needing a medium like air or water.

Front

How does a hot air balloon rise?

Back

Convection

Answer explanation

Hot air balloons rise due to convection. The air inside the balloon is heated, becoming less dense than the cooler air outside, causing the balloon to rise. This process is driven by the movement of warmer air upwards.

Front

Why is the air near the ceiling in a room warmer than the air near the floor?

Back

Convection

Answer explanation

The air near the ceiling is warmer due to convection, where warmer air rises and cooler air sinks, creating a circulation pattern. This process explains why the ceiling air is warmer than the floor air.

Front

The material in a lava lamp rises and falls.

Back

Convection

Answer explanation

The material in a lava lamp rises and falls due to convection, which is the movement of fluid caused by differences in temperature and density. As the lamp heats up, the warmer, less dense material rises, while cooler, denser material sinks.

Front

The sidewalk increases in temperature on a sunny day.

Back

Radiation

Answer explanation

The sidewalk heats up due to radiation, which is the transfer of heat through electromagnetic waves from the sun. Unlike conduction and convection, radiation does not require a medium to transfer heat.

Front

The sidewalk burns your bare feet in the summer time.

Back

Conduction

Answer explanation

The sidewalk burns your bare feet due to conduction, which is the transfer of heat through direct contact. Your feet absorb heat from the hot surface, causing discomfort.