1. The problem statement, all variables and given/known data A ball with the mass 0.48kg is hanging on a string. The ball is moved to the side and then released . When the string is vertical, the ball hits the side of a block which is at rest . The ball's position is then 1.5 lower down than from the beginning. a) the speed gets the ball ? I used the formulas mgh=mv^2/2 and the answer is 5.4 m/s b) The block has a mass of 2.5 kg. The block slides 0.65 m on the floor before stopping. The friction coefficient is 0.20. What is the block's initial velocity when hit by the ball? 2. Relevant equations 3. The attempt at a solution Now this is where it gets tricky. The ball's impulse must be the same as the impulse of the block. The ball's impulse is 0.48 * 5.4 = 2.592 . So that menas that the block's ivelocity 2,592 / 2.5 = 1,0368 m/s But it is wrong and I do not understand why. One of newtons law says that the impulse is the same in a collision.