Question

A car drives straight down toward the bottom of a valley and up the other side on a road whose bottom has a radius of curvature of 115 m. At the very bottom, the normal force on the driver is twice his weight. At what speed was the car traveling?

I have the formulas (v = 2pi*r / T) and (a = v2 / r). I know we take the radius of curvature to plug into the "r" value, but I'm stuck after that. Thanks everyone!