I have a bit of a problem with this question: A 0.30-kg puck, initially at rest on a frictionless horizontal surface, is struck by a 0.20-kg puck that is intitially moving along the x-axis with a velocity of 2.0 m/s. After the collision, the 0.20-kg puck has a speed of 1 m/s at an angle of 53 degrees to the positive x-axis. (a) Determine the velocity of the 0.30-kg puck after the collision. (b) Find the fraction of the kinetic energy lost in the collision. mass one= 0.20 kg mass two= 0.30 kg First off, is it possible to say that after the collision the two objects move off at an angle of 90 degrees from each other? The initial momentum of the stationary puck is zero, so according to the conservation of momentum I get 0.667 m/s as the final velocity of the 0.30-kg puck. Is this correct? Do I have to factor in seperate velocity along the x- and y-axis? For (b), I'm not sure what to do. How do I find the energy loss?