# Unbanked circular motion

1. Oct 15, 2008

### umeks17

1. The problem statement, all variables and given/known data
a highway curve has a radius of 122m. At what angle should the road be banked so that a car travellin at 26.8m/s (60mph) has no tendency to skid sideways on the road? (frictional force is zero)

2. Relevant equations

3. The attempt at a solution

2. Oct 15, 2008

### BerryBoy

Did you have a go at it?

Sam

3. Oct 15, 2008

### umeks17

no...can you help me to solve that question..

4. Oct 15, 2008

### BerryBoy

To start of you want to draw the setup as a force diagram at an arbitrary angle (called $\theta$ say), with:
- The normal reaction
- The centrifugal force from acceleration in a circle
- The Weight of the car

You need to find the angle at which all these forces are balanced. Does this help?

Sam

5. Oct 15, 2008

### umeks17

i will try it tonight

6. Oct 15, 2008

### umeks17

thanks a lot...a got it..:) huh