1. Car on an exit ramp a classic rotational motion & friction problem Rhine

2. The Problem r Suppose a car enters a flat (not banked) on-ramp at a constant speed of 50 mph (or, more generally, v). Assume S = 0.50 (or more generally, S ). If the car maintains this speed... a) What is the minimum safe radius that you, the civil engineer, should have used for the off ramp design? b) If the driver were to enter the turn at a higher speed, what would happen? c) Re-work the problem with a banked curve (bank angle of = 10, or more generally, ) v v Top View

3. Assumptions and intuition As the car is going through the turn, is the cars velocity changing or not? What type of force (or acceleration) is required for an object to follow a curved path? v r v Top View

4. Solving the problem i) Draw a FBD – of the FRONT VIEW of the car, as if it was headed straight toward you. Why do you need to use this orientation?? ii) Apply Newtons Second Law: iii) solve the problem for r v r v Top View

5. Banked off-ramp (bank angle = ) i) Redraw the FBD (FRONT VIEW of the car) ii) Apply Newtons Second Law: iii) solve the problem for r v r v Top View