If a car takes a banked curve at less than a given speed, friction is needed to keep it from sliding toward the inside of the curve (a real problem on icy mountain roads).
1. Calculate the minimum speed, in meters per second, required to take an 84 m radius curve banked at 11° so that you don't slide inwards, assuming there is no friction.
2. What is the minimum coefficient of friction needed for a frightened driver to take the same curve at 21 km/h?