# Homework Help: Banked Curve Physics Problem

1. Oct 3, 2004

### shawonna23

On a banked race track, the smallest circular path on which cars can move has a radius r1 = 111 m, while the largest has a radius r2 = 163 m. The height of the outer wall is 18 m.

(a) Find the smallest speed at which cars can move on this track without relying on friction.

(b) Find the largest speed at which cars can move on this track without relying on friction.

I think that I'm supposed to use this equation:
v= Square root of (r)(g)tan theta, but I don't know how to find theta?

2. Oct 3, 2004

### vsage

you can make a triangle out of the info given. Assuming the base of the track is on the x-z plane, you can create a triangle by taking a cross section pointing radially inward from the circle pointing in the positive y direction. Anyway that's not relevant just trying to give you a reference point. The two legs of the triangle would be (163-111) on the bottom and 18 going up. From this you can find an incline (theta) and you're solving for V.