I'm not sure if this question belongs to this forum or advanced phsyics.. but since I'm still in high school, I think this is the right forum. I'm doing physics questions based on roller coaster and am just a little bit confused on how to answer some questions. You know : Mass of each empty car and with passangers Total length of track Slope of lift Horizontal distance from bottom of lift to top Change in elevation at first drop Track length at the first drop Length of each car Questions 1: Calculate the total energy required to raise the train to the top of the first hill I'm thinking Eg - Ek will give you the answer, but I'm not sure. A friend suggested that the energy required is simply 0 since the train is moving at constant velocity to the top of the hill. Question 2: Apply the law of conservation of energy to determine the speed of the first car at the bottom of the first hill, assuming some energy is lost in overcoming friction (use a reasonable estimate) I'm just dead confused about this one. Any help is appreciated!!