When a given object moves a circular path, the centripetal force varies directly as the square of the velocity and inversely as the radius of the curve. If the force is 640lb for a velocity of 20mi/h and a radius of 5m, find the force for the

Question

When a given object moves a circular path, the centripetal force varies directly as the square of the velocity and inversely as the radius of the curve. If the force is 640lb for a velocity of 20mi/h and a radius of 5m, find the force for the 
velocity of 30mi/h and a radius of 4m.

Steve · Answer

F = kv^2/r If 640 = k(20^2)/5, then the new force will be 640*(3/2)^2/(4/5) = 1800