Basic physics, need some help :D Hi, first i would like to start of by saying that i am norwegian, so my english skills is not so good. But anyway, im having this test tomorrow and i need some help! Its about physics! I translated the task as good as i could! To sleds with elastic bumpers collides with eachother on a air-cussion course. Sled A's mass is 0,1kg, and sled b's mass is 0,4 kg. After the impact, sled A is moving at 0,5m/s and sled B is standing still. Calculate the speed of the to sleds before the impact. Thanks for all answears! If something is badly explained, please let me know!