Unit 3 Test

1. What force causes a ball to fall when John lets go of it?

• radiant energy
• gravity
• magnetism
• push

2. The sun is a star. Which of these best describes what makes up the sun?

• fire
• melted rock
• hot, glowing gases
• cold, glowing gases

3. The sun is a star that gives off energy. Which forms of the sun’s energy reach Earth?

• light and heat
• light and sound
• heat and electricity
• light and electricity

4. Which is true about birds and gravity?

• Birds avoid gravity by flying very quickly.
• Birds fly by using forces to overcome gravity.
• Birds fly by using heat to overcome gravity.
• Birds are too light in weight to be pulled by gravity.

5. Which set of tools would be the best to use to magnify the stars?

• binoculars and telescope
• microscope and telescope
• telescope and magnifying glass
• magnifying glass and binoculars

6. The sun is like other stars in many ways. How is the sun different from other stars?

• It is made up of gases.
• It is much closer to Earth.
• It is much larger than Earth.
• It is much hotter than Earth.

7. A computer sits on a desk. What is helping overcome the force of gravity on the computer?

• the desk
• the shape of the computer
• the direction the user faces
• the position of the keyboard

8. How might the water change in a swimming pool when it is heated by the sun’s radiant energy?

• The water turns red.
• The temperature rises.
• The temperature lowers.
• The temperature stays the same.

9. A teacher shows the class a picture of the sun and a picture of a star pattern, as seen from Earth. She points to the brightest star. What does the class know about the sun and the star from the pictures?

• The sun is larger than the star.
• The star is brighter than the sun.
• The star and the sun both give off light.
• The star and the sun are both the same size.

10. What force gives your body weight?

• Gravity
• Your feet
• Your head
• Earth’s magnetism