A physics major is working to pay his college tuition byperforming in a traveling carnival. He rides a motorcycleinside a hollow transparent plastic sphere. After gainingsufficient speed, he travels in a vertical circle with a radius of13.0 m. The physics major has mass 70.0 kg, and hismotorcycle has mass 40.0 kg.
a) what minimum speed must he have atthe top of the circle if the tires of the motorcycle are not tolose contact with the sphere?
b) at the bottom of the circle, hisspeed is twice the value calculated in part (a). what is the magnitude of the normal force exerted on the motorcylce by thesphere at this point?