His difference of 6mg, referred to as "six gees," is quite a difference for the body to tolerate. To avoid this stress, vertical loops are teardrop-shaped rather than circular, designed so that the centripetal acceleration is constant all around the loop. How must the radius of curvature R change as the car's height h above the ground increases in order to have this constant centripetal acceleration? The radius and the speed at the ground are R0 and v0 respectively. Express your answer as a function: R=R(h).