Solar Energy Review

1. Vocabulary and Content Solar Energy Review

2. Opaque objects, like bodies, block light from the Sun, creating a shadow on the opposite side of the object. How is a shadow created?

3. The compass needle always points to magnetic north. How does a compass work?

4. The shape and orientation of shadows change as the day progresses. The orientation and shape of outdoor shadows change because the position of the Sun changes continuously. The Earth rotates on its axis, which makes the Sun at a different position in the sky at different times of the day. The Sun rises in the east. When you are facing North, your shadow will be long and skinny and cast to the West. At 12:00 noon, your shadow will be short and squatty and will face toward the North. When the Sun sets, your shadow will be long and skinny and cast toward the East. Why do the position and length of a shadow change throughout the day?

5. A thermometer is a thin glass tube filled with colored alcohol. As the alcohol warms, it expands and travels up the tube. When the alcohol cools, it contracts and goes back down the tube. To use the thermometer, you put the bulb in the material to be measured for temperature. Explain how a thermometer works.

6. Earth materials that heat up quickly are those that are dry and solid. Dark colored ones will heat up more than light colored ones. Describe earth materials that heat up quickly.

7. Water is a heat sink. It can absorb a large amount of heat for its volume and release energy slowly. Tell why water absorbs heat quickly, but it cools down slowly.

8. Black plastic absorbs solar energy, which it transfers to the water. White plastic reflects solar energy, so the water in those containers did not heat up as much. Describe why the solar water heaters with black plastic in them heated up faster than those with white plastic in them.

9. A cover keeps the heat inside the container. It also prevents energy transfer by keeping the water from coming in contact with cooler air around it. Describe why solar water heaters with lids heat up more than those without lids.

10. The ovenwas in direct sunlight. The slanted side with the transparent window let in the sun’s energy. The energy was absorbed with the solar collector (black paper) in the bottom. It trapped the heat inside. The heat energy was transferred to your food, which heated it to make your s’mores. How was your solar oven able to cook your s’mores?