... 23a. The Centrifugal Force . ... You can also view this problem from the point of view of the outside world, using the centripetal force, but it is not as easy. At point A, on the top of the loop, both gravity and the centripetal force point downwards. ... A car going around a loop, with radius R and velocity V, is accelerating at a rate of V 2 /R towards the center (as long as it stays on the rails), and is therefore subject to a centripetal force mV 2 /R, also directed to the center. ...