# Force and Orbit Speed

http://www.science27.com/forum/coworbit.jpg [Broken]

How much relative stronger force would it require to keep a bull in orbit when the radius was 4 times shorter.

And how can this are calculated...?

(The bull only wants to move straight ahead , weight and speed is the same)

4 times ?
2 times ?
8 times ?
Or ?

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## Answers and Replies

http://www.science27.com/forum/coworbit.jpg [Broken]

How much relative stronger force would it require to keep a bull in orbit when the radius was 4 times shorter.

And how can this are calculated...?

(The bull only wants to move straight ahead , weight and speed is the same)

4 times ?
2 times ?
8 times ?
Or ?

You would need to use the centripetal force equation. If the radius was four times smaller, the force needed to keep the bull in orbit would be << answer deleted by berkeman >> times bigger.

Last edited by a moderator:
berkeman
Mentor
http://www.science27.com/forum/coworbit.jpg [Broken]

How much relative stronger force would it require to keep a bull in orbit when the radius was 4 times shorter.

And how can this are calculated...?

(The bull only wants to move straight ahead , weight and speed is the same)

4 times ?
2 times ?
8 times ?
Or ?

Use the equations for centripital force. You can read about them here:

http://en.wikipedia.org/wiki/Centripital_force

So based on that wiki page, what do you think the answer is?

Last edited by a moderator:
berkeman
Mentor
You would need to use the centripetal force equation. If the radius was four times smaller, the force needed to keep the bull in orbit would be << answer deleted by berkeman >> times bigger.

(This is a schoolwork-like question. Please do not give the answer. Thanks.)