1. ISAAC NEWTON AND GRAVITY An Invisible Force

2. Gravity Every object pulls on every other object with an invisible force called gravity. There is gravity between you and your toy car, but you won’t notice it because it is so weak.

3. Gravity You can, however, feel the pull between you and the Earth. That’s because the force of gravity depends on an object’s mass, and the Earth has a lot of mass.

4. Gravity The Earth has so much mass that it pulls everything downward toward its center including the oceans and air. Even the Moon stays above the Earth because of gravity.

5. Isaac Newton Over 300 years ago a scientist named Isaac Newton explained this invisible force of gravity.

6. Newton’s Discovery Newton was sitting in his garden when he saw an apple fall from a tree. He decided that some force must be pulling the apple to the ground. He called it gravity.

7. Test Your Knowledge You already know a lot about gravity. That’s because it’s at work all the time. Let’s test your knowledge.

8. Is Gravity Working? Is gravity working? yes or no

9. Is Gravity Working? Is gravity working? yes or no

10. Is Gravity Working? Is gravity working? yes or no

11. Is Gravity Working? Is gravity working? yes or no

12. Is Gravity Working? Is gravity working? yes or no

13. Is Gravity Working? Is gravity working? yes or no

14. Is Gravity Working? Is gravity working? yes or no

15. Is Gravity Working? Is gravity working? yes or no

16. Is Gravity Working? Is gravity working? yes or no

17. Fighting Against Gravity We can overcome gravity, but we have to use force to do it.

18. More About Gravity Hang on! There’s more to come!

19. Picture Credits Pictures are courtesy of Microsoft clip art.