Hey all, here's a question from one of my homework sets, any help is greatly appreciated. 1. The problem statement, all variables and given/known data I've included a diagram of the situation. Basically, I have to find out how long it takes the block to reach the end of the ramp, the spring is massless, and friction is a factor in this problem. edit: Mass of block is .1KG, not 100KG. The picture does not show this very clearly. 2. Relevant equations Newton's Second Law: F = MA Potential energy of a spring: Us= .5KX^2 Friction: F = kN 3. The attempt at a solution I know that to get started in this problem, I will first need to find the magnitude of each force acting on the block, and in turn find the net force. My reference frame is such that +X lies parallel to the ramp in the direction the block is moving, and +Z is the direction perpendicular to the ramp. Here's my attempt to find the forces acting in the +X direction (at the instant before the Block loses contact with the spring): Gravitational, I know that a portion of the gravitational force will be resisting the block's movement, but I'm running into my first problem here. I found the total gravitational force to be MG = .1kg * 9.8m/s2 = .98N. However, I'm having problems setting up a triangle to find the ratio of how much the .98N is in the +X direction, since the force is not running parallel with the hypotenuse. How do I find it? Spring Energy, I know that the spring constant is 400N/m, and it is compressed .1m. U2 = .5*400N/m*(.1m)^2 = 2.0J So the speed just after launch by conservation of energy is: 2.0J = .5*.1kg*v2 V = 6.32m/s However I'm not sure if this is entirely useful, as I'd like to know the force on the block, how do I find this if I don't know the acceleration? Friction, I know friction on an incline depends on the normal force, so: Fkf = .250*.1kg*9.8m/s2*cos(10°) = .241N in the -X direction. I think I have the force of friction correct, so I'm 1 for 3 so far. If anyone could help me out with finding the gravitational force and the force for the spring I'd greatly appreciate it.