Maximum Velocity Around a Curve

[Redrover33]

Homework Statement

A motorcycle (290kg) and rider (55kg) crest the top of a hill at a steady speed of 25m/s. The hill has a radius of curvature of 126m.
a) What is the magnitude of the normal force experienced by the rider?
b) What is the magnitude of the centripetal force experienced by the motorcycle?
c) At what speed would the motorcycle and rider lose contact with the surface of the hill?

Homework Equations

Fn = m*g
A = (v^2)/r
Ff = Us*Fn

Where Fn = Normal Force, Ff = Frictional Force, Us = Max static friction

The Attempt at a Solution

So a) and b) are no problem but its c) that has been bugging me all night. From what I can tell, there isn't enough information to find the maximum speed the rider can go. Am I wrong? I know that the centripetal acceleration x mass is = to the frictional force but we aren't given the maximum frictional force or the coefficient of friction.

 

[ehild]

No, it is not friction that keeps the motorcycle on its track on the hill. What you think of, it is a horizontal curved road.

Draw a picture with a hill and the motorcycle on top. What forces act on the motorcycle and man? Find the normal force and note that the road can only exert an upward force. If this normal force should be zero or negative to make the crest, the motorcycle loses contact with the road. ehild