A car of mass 1000 kg is traveling over the top of a hill as shown in Figure P5.21.?

(a) If the hill has a radius of curvature of 40 m and the car is traveling at 15 m/s, what is the normal force between the hill and the car at the top of the hill??

(b) If the driver increases her speed sufficiently, the car will leave the ground at the top of the hill. What is the speed required to make that happen?

Figure P5.21