What Range of Speeds Allows a Car to Safely Navigate a Wet, Banked Curve?

[botab]

Hello PF, I need some assistance with this problem.

A curve of radius 61 is banked for a design speed of 89 .

If the coefficient of static friction is 0.32 (wet pavement), at what range of speeds can a car safely make the curve? [Hint: Consider the direction of the friction force when the car goes too slow or too fast.]

how should I start this question @_@

 

[Kurdt]

Hello botab. Units would help anyone looking at this question. numbers are meaningless if they don't have any units to tell you what they are measuring.

Basically you're going to need to consider the circular motion of the car. When the car travels in a circle there is a centrifugal force which is opposed by the friction between the road and the tyres. At some speed the centrifugal force will be too great for the friction to cope with and the car will spin out.