Hello all, I never really had a great deal of trouble with physics until just recently and this place looks like a great place to learn. I am having problems with the following question: A frictionless track is to be built as shown, with L=3.20 m and H=2.90 m. In order to get the cart to slide from the top to the end of the track in the minimum time, how long should the distance D be? Assume that the speed of the cart on the horizontal surface is the same as at the bottom of the ramp. Hint: A minimum or maximum value can be found using derivatives. A picture to go along with the question How would I go about in setting this problem up? I am just clueless one where to start. I believe that I have to set up some type of formula, take the derivative of it and solve for D? Thank you for your time and help.