Alright, I'm having trouble with this problem, but I know that it's easy and simple. If the car starts at height h= 3.00 R and the radius is R_1 = 25.0 m, compute the tangential acceleration of the passengers when the car is at point C, which is at the end of a horizontal diameter. Picture: http://session.masteringphysics.com/problemAsset/1041727/8/YF-07-32.jpg So h= 75 m and R = 25 m. I know that the tangent acceleration is the derivative of the velocity equation with respect to time, but I can't find out how to do that exactly. In early parts of this problem, I found the velocity at point C to be 31.3 m/s and the radial acceleration to be 39.2 m/s^2 This problem was found in my energy homework, so I know that I'm messing with mgh and 1/2mv^2 and such. Thanks!