Name: _______________________________________________ __
Date: ______________________
Background Questions
Think about a hot summer day at the beach.
Describe how the sand feels on your bare feet. ____________________________________
Describe how the water feels on your bare feet. ________________________________________________
Why do they feel differently? ________________________________________________________________
Key Question: How does the sun affect the heating of Earth’s different surfaces?
Form a Hypothesis
Example Hypothesis:
If land and water are heated for the same amount of time, then… land will heat faster than water.
Experiment
Remember, an independent variable is the thing in the experiment that is being changed by the scientist.
For this experiment, the independent variable is: the amount of time in the Sun.
Remember, a dependent variable is the thing that is affected by the independent variable. It is the thing
being measured. For this experiment, the dependent variable is: the temperature of the surfaces.
Heating Up
Cooling Down
Time (min.)
Sand Temperature (Co)
H2O Temperature (Co)
0 (starting time)
25 oC
24 oC
2
26 oC
25 oC
4
27 oC
25 oC
6
35 oC
26 oC
8
38 oC
26 oC
10
40 oC
26 oC
12
43 oC
27 oC
14
48 oC
28 oC
16
41 oC
27 oC
18
39 oC
27 oC
20
37 oC
26 oC
22
35 oC
26 oC
24
33 oC
26 oC
26
32 oC
25 oC
28
30 oC
25 oC
30
27 oC
25 oC
Graph Your Results
Temperature (Co)
Key:
Sand =
Water =
Time (min.)
ENDING
temperature:
STARTING
temperature:
Total change in
temperature:
1.
HEATING UP
Sand
Water
48
28
25
24
23
4
Which surface had a greater change in
temperature over time when HEATING UP?
Sand or Land
2. Which surface took the longest to HEAT UP?
Water
COOLING DOWN
Sand
STARTING
temperature:
ENDING
temperature:
Total change in
temperature:
Water
41
27
27
25
14
2
3. Which surface had a greater change in
temperature over time when COOLING DOWN?
Sand or Land
4. Which surface took the longest to COOL DOWN?
Water
Conclusion
1. Looking back at the questions from the beginning, why does the sand feel differently than the
water during a hot summer day at the beach (how does the sun affect the heating of Earth’s
different surfaces)?
Land heats and cools faster than water. Land absorbs more of the Sun’s radiation while water reflects
some of the Sun’s radiation. Water also has a greater heat capacity, meaning that water is able to absorb a
high amount of heat before increasing in temperature.
Application
2. How might location near an ocean have an influence on the temperature of a city?
A city near an ocean would be warmer in the winter because the ocean has been heated all summer and
holds on to heat, which warms the air throughout much of the winter. Water takes longer than land to
heat up and cool down.
3. So, let’s relate that to this next scenario by looking at a map. Your Grandmother lives in Poplar
Bluff, Missouri. Every winter, she likes to fly to Norfolk, Virginia because she says it’s a little warmer
there. What might be the explanation for the temperature difference?
Norfolk, Virginia is located near the Atlantic Ocean. Because water heats and cools very slowly. Now that
it is winter the ocean is still holding on to some of the heat from the summer. So, the air in Norfolk would
be slightly heated by the ocean water. Poplar Bluff is surrounded by only land. Land loses heat quickly.
So, during the winter the land will have lost the heat and is unable to heat the air above it, making it colder
in Poplar Bluff.