1. The problem statement, all variables and given/known data A merry-go-round is sitting in a playground. It is free to rotate, but is currently stationary. You can model it as a uniform disk of mass 220 kg and radius 100 cm (consider the metal poles to have a negligible mass compared to the merry-go-round). The poles near the edge are 86 cm from the center. Someone hits one of the poles with a 9 kg sledgehammer moving at 15 m/s in a direction tangent to the edge of the merry-go-round. The hammer is not moving after it hits the merry-go-round. How much energy is lost in this collision? (enter a positive number for the absolute value in Joules) 2. Relevant equations conservation of momentum KE of rotation =.5mv2 KE of linear motion = .5Iω2 Lost of energy=KErot-KElinear 3. The attempt at a solution I assume that hummer hit pole tangentially and collision was elastic. My way of thinking is that energy transfer of KE of linear motion to KE of rotation. Thus I need to find KElinear and KErot. Where KElinear is easy to find. To find KErot, first, apply conservation of momentum. mhvh=mdvd Linear momentum was transferred to rotational motion. Where vd is tangential velocity of disk. vd is velocity of hummer. Then, v=ωd (d-distance from center to metal pole) From these, I can find ω and put it into my KErot Than I can find my energy loss. Right?