TO ABSORB OR REFLECT……....
………..THAT IS THE
energy does not stay in the same form as it flows through the Earth
system. Energy from the sun enters the Earth system as sunbeams and exits
the Earth system as heat. What happens to it in between? (A very good
question, my clever student!!) Energy is transferred from one form to
another as it flows through the Earth system. For example, energy
enters the atmosphere as sunlight. When the sunlight strikes an apple tree
leaf the energy is absorbed and some of it is transferred, through
photosynthesis, to chemical energy that is stored in the form of
sugar. When you eat that apple, some of the energy stored in the sugar is
transferred, through cellular respiration, to the kinetic energy that you use
to dance all night at the Prom. Dancing, in turn, causes some of your
energy to be transferred to heat energy which warms up the gym and eventually
flows out of the Earth’s systems into space.
As you know,
energy undergoes many changes as it flows through the Earth’s system. In
this assignment you will examine how light energy from the sun is converted
into heat energy by various materials. Some materials tend to absorb solar
energy and convert the solar energy to heat. Other materials are more
effective at reflecting solar energy.
· Cover each cup with a
different material-white paper, black construction paper, aluminum foil, and
one with no covering.
· Fill each plastic cup
two-thirds full of water that is about room temperature.
· Place a thermometer in
each cup. (Or margarine, if you don’t have thermometers.)
· Place all four
containers in sunlight for sixty minutes.
· Take temperature
readings initially and every five minutes. (Or estimate the percentage of
margarine that is melted in each cup.)
· Write down your data on
Send me the following.
Use complete sentences to answer the questions.
1. Your data table.
2. Make a graph of your
data. Plot each container's data on the same graph (temperature vs. time)
in a different color.
3. What were the
temperature readings for each of the containers when you started?
4. What were the
temperature readings for each container at the end of the time?
5. How do the initial
readings compare with the final readings?
6. What happened to the
energy that arrived in the form of sunlight?
7. What evidence do you
have that sunlight was reflected or absorbed?
8. If all of the cups
received the same amount of sunlight then how can you explain why they have
9. Predict what will happen
to the heat energy that was absorbed by the water in the cups.
Use your knowledge about
how energy is absorbed or reflected to answer the following questions.
10. Apply your knowledge
about how the various materials reflect and absorb sunlight to common
situations. For example, most people living in Africa wear white or light
colored clothing because it reflects sunlight and is therefore
cooler. Give three examples of HOW various materials are used to
absorb or reflect sunlight.
11. Why is it usually cooler
in the country than it is in the city?
12. If plants absorb
sunlight why don’t they produce a large amount of heat? What energy
conversion is taking place in plants?
13. Explain how the transfer
of solar energy affects the atmospheric system.
14. Explain how the transfer
of solar energy affects the hydrologic system.
15. Explain how the
transfer of solar energy affects the geologic system.
16. Explain how the transfer
of solar energy affects the biologic system.
GOOD LUCK AND HAVE FUN!!!
- four thermometers if possible.
- white construction paper