physics
posted by Anonymous .
A sports car of mass 1300 kg (including the driver) crosses the rounded top of a hill (r = 86 m) at 23 m/s. Determine the normal force exerted by the car on the 74 kg driver. Determine the car speed at which the normal force on the driver equals zero.

Let the normal force exerted by the seat on the driver be F.
M g  F = M a = M V^2/R
F = M (g  V^2/R)
Use that equation to compute F when V = 23 m/s.
The mass cancels out.
For the last part, solve for V when F = 0.
V = sqrt(Rg)