# Homework Help: Roller coaster friction problem?

1. Nov 17, 2012

### bohobelle

1. The problem statement, all variables and given/known data
You're at the amusement park and your friend wants to go on the "Barrel of Fun," where the ride is a cylinder with a vertical axis. You stand against the wall and after the ride is spinning fast enough, the floor drops out beneath you. What is the minimum coefficient of friction necessary to keep you from falling down once the floor is gone? The ride takes two seconds per revolution.

2. Relevant equations
Moment of intertia of a cylinder = MR^2

3. The attempt at a solution
I honestly have no idea what I'm doing! My teacher tends to teach us one lesson in class and then give us a ridiculously complicated problem that we are not prepared to do for homework.

I think that you need to find rotational velocity and then transform that into acceleration, and then find friction from that, but I am not sure?

2. Nov 17, 2012

### voko

3. Nov 17, 2012

### bohobelle

How would I get from acceleration to friction?

4. Nov 17, 2012

### bohobelle

I got 658.69 as the coefficient of friction, does this seem correct?

5. Nov 17, 2012

### voko

Explain how you got that.