1. The problem statement, all variables and given/known data A merry-go-round is a common piece of playground equipment. A 4 m diameter merry-go-round with a mass of 220 kg is spinning at 16 rpm. John runs tangent to the merry-go-round at 5.0 m/s, in the same direction that it is turning, and jumps onto the outer edge. John's mass is 31 kg. What is the merry-go-round's angular velocity, in rpm, after John jumps on? 2. Relevant equations Li = Lf KE = 1/2mv^2 KE = 1/2Iw^2 3. The attempt at a solution I tried doing the following: Li = Lf (.5)(220)(2^2)(16) = (.5(220) + 31)(2^2)wf wf = 12.482 rpm That appears to be wrong. I also tried using: 1/2Iw^2 (KE of John and merry-go-round) = 1/2mv^2 (KE of John) + 1/2Iw^2 (KE of merry-go-round) and I also do not get the right answer. Does something have to be converted such as 5 m/s to rpm? Thank you!