Name ______________________________________________________ Class ________

Sunlight Angles Lab The Earth is a sphere, so sunlight doesn’t hit it evenly. Indirect light is light that hits the Earth on an angle. In this lab, you will explore how direct and indirect sunlight affects the energy that Earth receives. Materials Needed:

• incandescent light bulb • flashlight • white paper • colored pencils

Part 1: Light Bulb 1. Hold your hand straight up and down about 10 cm from the light bulb and feel the heat. Why

do you think the heat from the light bulb is spread out evenly across your palm? Explain. __________________________________________________________________________________________________________________________________________________________________

2. Keep your hand straight up and down, but this time, move your hand different distances away from the light bulb. Describe the differences in temperature you felt at different distances. __________________________________________________________________________________________________________________________________________________________________

3. Next, hold your hand at an angle next to the light bulb. Keep your fingers about 10 cm from

the light bulb, but angle your palm so that it is further back. How is the warmth you felt on your fingers different from your palm? Explain. ____________________________________________________________________________________________________________

4. Why do you think you felt a difference in temperature when you held your hand at an angle,

but not when you held your hand straight up and down? Explain. __________________________________________________________________________________________________________________________________________________________________

Part 2: Flashlight 1. Hold the flashlight about 3 cm directly above the white paper as shown in diagram A. Have

your partner use a red colored pencil to trace the outer ring of the flashlight’s light on the paper.

2. Continue to keep the flashlight about 3 cm above the paper, but angle the flashlight just slightly

as shown in diagram B.. Use an orange colored pencil to trace the outline of the flashlight like you did in the previous step. Do not trace beyond the paper.

3. Angle the flashlight back a little further, as shown in diagram C. Trace the outline of the

flashlight using a blue colored pencil like you did in the previous steps.

Analyze Your Results 1. What did the flashlight represent? What did the paper represent?

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2. Explain how the area that received light changed as the flashlight’s angle was tilted: _____________________________________________________________________________________________________________________________________________________________________

3. No matter what angle you held the flashlight, there were areas on your paper that received more direct sunlight than indirect sunlight. Where did you find the direct sunlight? Where was the indirect sunlight? (HINT: Which area of the lighted surface was brighter? Which area was darker? Use the flashlight again if you are not sure.)

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4. Which was stronger, the direct sunlight or indirect sunlight? How could you tell? Explain.

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5. As you tilted the flashlight, why do you think the size of the area that received light changed? What happened to the concentration (amount) of light in any one area? Explain.

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6. The diagram above shows the angle of the sun in June and in December. How does the

angle of the sun relate to the temperature on Earth? Why do you think this is? Explain. ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

NOTE:  Both  of  these  pictures  show  the  sun  at  the  same  time  of  day:  1:00p.m.  

7. The diagram above shows the angle of the sun’s rays along the Equator and in the

Northern Hemisphere. Please answer the following questions using details: a. Why would locations along the Equator be warmer than locations in the Northern Hemisphere? b. How does the angle of sunlight affect the energy that these locations receive? Explain.

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