1. The problem statement, all variables and given/known data A 10 kg initially at rest is pulled 13m across a floor by a 50N force. if friction does 380J of work over this distance, what is the block's final velocity? http://imgur.com/a/zM1MX 2. Relevant equations W=Fd, Ek=1/2mv^2 3. The attempt at a solution Since the block was at initially at rest the Energy initially is 0, so I set up the equation like this 0 = Ek after + Efriction. Since friction is 380J i moved it to the other side, then did 1/2mv^2 = 380J to find V which I got 8.72 m/s, but the answer is 7.3m/s. Did I set up the equation wrong?