# Homework Help: Normal Force on a Ferris Wheel

1. Nov 12, 2008

### thekeyofheart

1. The problem statement, all variables and given/known data
What is the normal force acting upon a person at the top of a ferris wheel that has a radius of 60 meters, and is travelling at a rate of 25 meters/second?

2. Relevant equations

Centripetal Force = Gravity Force - Normal Force

Normal Force = mv²/rtmg

Gravity Force = mg

3. The attempt at a solution

The only way I know of to solve this problem is if the mass is known, but in this question the mass is not given.

Centripital acceleration = 10.42 m/s²

I tried drawing a free body force diagram

What is the next thing I should be considering?

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Last edited: Nov 12, 2008
2. Nov 13, 2008

### tiny-tim

Welcome to PF!

Hi thekeyofheart! Welcome to PF!

Well, you're certainly right … you do need to know the mass to calculate N

I think you'll have to call the mass "m", and give an answer as a multiple of m.

(unless … perhaps the question is asking for the "g-force", which is really the acceleration as a multiple of g, and for which, of course, you don't need the mass)

3. Nov 13, 2008

### thekeyofheart

Re: Welcome to PF!

Thank you for the welcome, tiny-tim! I have been a follower for a while, but I only recently made an account, and this was my first post.

I know I tend to overanalyze stuff like this, and I kept trying to figure out a way to complete the problem without knowing the mass. I am using m as a variable, and when I get the expected answer I will report back =)