# Homework Help: Circular Motion and Banked Curves

1. Feb 24, 2010

### erin.grae

1. The problem statement, all variables and given/known data
A concrete highway curve of radius 60.0 m is banked at a 11.0 degree angle. What is the maximum speed with which a 1500 kg rubber-tired car can take this curve without sliding? (Take the static coefficient of friction of rubber on concrete to be 1.0.)

2. Relevant equations
w f 2 = w i2* t + 1.2 * alpha * t
theta f - theta i = w i t + t/2 alpha t 2

3. The attempt at a solution

Okay, I drew a picture of the problem and I tried to find all the forces acting on the car but I really don't think I've got them all. I know there's the usual gravity, normal force, and centripetal acceleration but I'm not sure if the equations I referenced above are even really relevant.

2. Feb 24, 2010

### rock.freak667

In your FBD, centripetal force is not to be on there, centripetal force is a resultant force.

The resultant normal force (perpendicular to the plane) is zero. You should now be able to find the normal reaction.

Friction=μR.

If the car slides down the plane, then friction acts up the plane. What do the resultant of these two force give?