# Banked Curve with Friction Problem

1. Sep 30, 2004

### ruck101

Hey all! Brand new to PF. Anyway, I'm having trouble with a problem involving centripital force. Here are the givens:

Friction coefficient = .49
Angle = 19 degrees
mass= 1200 kg

Question - How fast can the car take the curve without skidding to the outside? Thanks ahead of time!

By the way, yes, I have attempted this problem, just so nobody thinks I'm trying to get my homework done for me.

Last edited: Sep 30, 2004
2. Sep 30, 2004

### Pyrrhus

Show us your attempt then. and Welcome to PF!

3. Sep 30, 2004

### ruck101

Banked Curve

Hehe, guess I should have done that in the first part. Anyway, I drew a freebody diagram and got the Normal Force = 11119 N, and the Friction force = Normal x Coefficient = 5448 N. Is that the only centripital force or is there also the sin component of the weight? I've added sin (mg) and the friction force together and plugged it into V^2= Centripital Force x radius/ mass. And I get the wrong answer, or so my online homework says. I get around 18 m/s.

4. Sep 30, 2004

### Staff: Mentor

How did you find the normal force?

Realize that when the car moves at maximal speed, there are three forces acting on the car: weight, friction (which way does it act?), and the normal force. In the horizontal direction, there is centripetal acceleration; in the vertical direction, equilibrium.