1. The problem statement, all variables and given/known data A man of mass 50kg is riding a horse of mass 450kg at a steady speed of 10m/s. The horse stops suddenly and the man is thrown forwards. Find the speed with which the man is thrown forwards. Applying law of conservation of momentum, the resulting speed is 100m/s. Poor man. However, I checked whether K.E. is conserved or not in such a situation. To my surprise, the K.E. after is greater than that before!!!!!!!!!! 2. Relevant equations K.E = 1/2 m v^2 3. The attempt at a solution According to the law of conservation of energy... energy can neither be created nor destroyed, so what is wrong here?