You: 63.5 (Say you weighed 140 pounds, your mass would be 63.5 kg)

The force of gravity between you and the earth is:

F = (6.67*10^-11) (5.95*10^24 kg)(63.5 kg)

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(6,378,000 m)^2

F = 620 N

If we redo the equation for the moon, replacing the earth's mass and radius with that of the moon, we get:

F = 103 N

So when Neil Armstrong said "One small step for [a] man, one giant leap for mankind" on the moon in 1969, he was under only 1/6 Earth's gravity!

As you can see, the force of gravity on a person on the earth is greater than the force of gravity on a person on the moon. In a nutshell, this is because the earth has more mass than the moon.

Objectives:

1. Students will learn that balls made of different materials bounce to different heights.
2. They will learn about potential and kinetic energy.
3. Students will learn that the amount of gravity present affects the height at which something or someone can bounce or jump.

Vocabulary:

• Energy: The measure of a system's capacity to do work.
• Potential energy: Energy due to an object's position or orientation.
• Kinetic energy: Energy due to motion. Energy that an object has because it is moving.

Materials needed:

Per group:

4 of the following:

• super ball
• rubber baseball
• Ping-Pong ball
• Nerf ball
• golf ball
• tennis ball
• marble
• a piece of paper about 1 meter x 1 1/2 meters
• masking tape
• meter or yard stick
• different-colored markers
• sticker dots in colors corresponding to marker colors