How far from Earth's center is the center of mass of the Earth Moon system?

A 28 kg child sits at one end of a 3.5 m long seesaw. Where should her 65 kg father sit so the center of mass will be at the center of the seesaw?

Roughly where is your center of mass when you're standing?

Earth is gravitationally attracted to a. Mercury. b. the moon. c. the sun. d. All of the above

Describe ways in which tides could be affected if Earth had two moons.

If a baseball were the size of Earth, about how large would its atoms be?

Considering that millions of species have lived on Earth, why are there relatively few fossils?

One kg weighs $10$ N on Earth. Would it weigh more or less on the Moon?

Compare the fuel required for a trip from Earth to Moon with that required for the return trip.

If the temperature of the earth warms up how does the carbon dioxide cycle respond?

Applying Ideas How would seasons be different if Earth was not tilted on its axis?

How does ellipticity affect the total amount of solar energy that reaches Earth?

Understanding Relationships How can it be that Earth is at perihelion during wintertime in the Northern Hemisphere?

Earth is gravitationally attracted to a. Mercury. b. the moon. c. the sun. d. All of the above.