# Homework Help: Helpy me quick question

1. Jan 3, 2010

### zelda1850

1. The problem statement, all variables and given/known data

As a meteor moves from a distance of 16 earth radii to a distance of 2 eath radii from the center of earth, the magnitude of the gravitational force between the meteor and earth becomes

1) 1/8 as great
2) 8 times as great
3) 64 times as great
4) 4 times as great

2. Relevant equations

i think theres an equation to it but i dont know

3. The attempt at a solution

i know that double the radius is 4 times the force but im not sure how to answer this question

2. Jan 3, 2010

### Dick

The equation you want is called 'Newton's law of universal gravitation'. It's really pretty famous. Can you try and find it?

3. Jan 3, 2010

### zelda1850

oh is choice 3 correct?

4. Jan 3, 2010

### Dick

I would feel better answering that if you explain why you think so.

5. Jan 3, 2010

### zelda1850

emm i did 16 square divided by 2 square and got 64

6. Jan 3, 2010

### Dick

That's good. It's right.

7. Jan 3, 2010

### zelda1850

oh thx for the help