Designing a Safe Curved Roadway: AP Physics Problem for Civil Engineers

[daniel-c]

A civil engineer is asked to design a curved section of roadway that meets the following conditions: With ice on the road, when the coefficient of static friction between the road and rubber is 0.08, a car at rest must not slide into the ditch and a car traveling less than 50 km/h must not skid to the outside of the curve. What is the minimum radius of curvature of the curve and at what angle should the road be banked?

 

[Dick]

Any thoughts on this? What forces acting on the car when it's at rest? What changes when it's in motion (rotational acceleration?). The rules of the forum are that you have to start trying to solve the problem before people can jump in and help.