Heating and Cooling of Earth's Surface

Heating Up Cooling Down

The physics of the beach

Multiple Choice

What is the main source of natural heat energy on the Earth?

• the deserts

• the sun

• geothermal (earth's core)

• summers

Earth is heated each day by the sun

• The sun heats the air, land and water

• Air, land and water each heat up differently

• Each has a different SPECIFIC HEAT CAPACITY

The ocean, air, and land heat up at different rates.

Water has a high specific heat capacity (4.18 J/gK)

Sand is lower (0.58 - 1.04 J/gK)

Air is 1.01 J/gK

Multiple Choice

If the specific heat capacity of water is about 4 times larger than sand, then...

• Sand heats up faster than water

• Water heats up faster than sand

• Sand and water heat up the same rate

• Sand cannot get hotter than water

Multiple Choice

If you've been to the beach on a hot day, the dry sand is ______ compared to the water

• hotter

• colder

• same temperature

Daytime Beach

Water has a higher specific heat than sand, it heats up slower. The sand has a lower heat capacity and heats up fast

Beach at Night

At night, the water cools off slower. The sand cools off faster. This is why the ocean may be warmer than the beach at night!

Try swimming at night... if you dare!

Multiple Choice

Why does the sand get hotter than the ocean water?

• Sand takes longer to heat up

• The water heats up quickly

• The sand has a low specific heat capacity

• The water has a low specific heat capacity

Open Ended

Image you wanted to swim in the ocean when the air, sand, and ocean are around the same temperature. What time of day would be a good time to go? Explain why you gave the answer you did.