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.

Answer 1

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)