Gravity, Weight, and Mass:

1. Gravity, Weight, and Mass: What does this have to do with you?

2. Gravity • A force that pulls us and everything else toward Earth • Every object in the universe has gravity • Why? So we do not float into space

3. Mass • The amount of “stuff” (matter) in an object • Mass does not change

4. Weight • Measurement of the force on an object caused by gravity • Weight does change depending on gravity

5. How does this all relate? • Well, you or something else will weigh less or more depending on where you are in our solar system. • The more mass an object has, the more it weighs because of the more gravity required to pull it down. • On Jupiter, for example, you will weigh more. Jupiter has more mass than Earth; therefore, more gravity is needed.

6. Cont. • On the moon, you would weigh less because the moon has less mass. • In fact, the moon’s gravity is 1/6 of Earth’s.

7. Cont. • Your weight would change at these times. However, your mass would remain the same. • You would not suddenly be fatter or skinnier. The “stuff” that makes you up (matter) would be the same.

8. Let us say I weigh 115 pounds on Earth. (I wish!)

9. On Jupiter, I would weigh about 270 pounds (lbs.) I would not be fatter, but I would weigh more because Jupiter has more mass than Earth and more gravity is needed.

10. On the moon, I would weigh about 20 lbs. I would not be skinnier. Less gravity would be needed because the moon has less mass than Earth.

11. To find my weight, I multiplied mass by gravity.

12. Moon: 1/6 Earth’s Gravity On Earth, I weighed 115 pounds. My weight on the moon was about 20 pounds. Is this 1/6 of my weight on Earth? How do you know?

13. Now you will use your weight (pretend) to determine your weight on the moon and other planets.