PHYSICS
posted by J .
A banked circular highway curve is designed for traffic moving at 60 km/h. The radius of the curve is 205 m. Traffic is moving along the highway at 40 km/h on a rainy day. What is the minimum coefficient of friction between tires and road that will allow cars to negotiate the turn without sliding off the road?

Use the 60 km/h "naked curve design speed" to determine th banking angle, A. First convert the speed to m/s.
(M V^2/R) = M g sin A
sin A = V^2/(Rg)
If the car is travelling at a slower speed, the friction force plus the gravity component must exceed the centripetal force in the radial direction along the surface. Use that fact to determine the required friction coefficient. 
Somehow the word "banked" got typed as "naked". I must not be quite awake yet