1. The problem statement, all variables and given/known data A 60,000 kg train is being pulled up a 1% gradient by an engine exerting 3 kN. The frictional force opposing the motion of the train is 4 kN. The train’s initial speed is 12 m/s. Through what horizontal distance will the train move before it’s speed is reduced to 9 m/s? The answer is 275m 2. Relevant equations Fpush/pull=mgsinθ (component along the ramp)+Ff (friction force) I know that the equation above is used to solve the problem but i do not understand it or know how to use it 3. The attempt at a solution s=ΔE/F Vf=1/2mv^2=2430000 Vi=1/2mv^2=4320000 ΔE=-1890000 then i did not know how to work out the force to put it in the s=ΔE/F formula to work out the horizontal distance. But i know my attempt is completely wrong, my major problem with friction problems is identifying which forces are acting on the object and the types of forces and then finding the right formula to work out the answer. Any help very much appreciated, thank you.