There is a train of length d and speed v. It is heading towards a hill with height h and length of each side l. What velocity requirement must be met so that the train can go up and down the hill?
The Attempt at a Solution
I'm basically stuck at conversation of energy. Train needs to have kintetic energy equivalent to potential energy mgh, but calculating v from this equation seems pointless since it doesn't include either length. I have no idea how to include either of them.