1. The problem statement, all variables and given/known data A disk-shaped merry-go-round of radius 2.63 m and mass 155 kg rotates freely with an angular speed of 0.686 rev/s. A 59.4 kg person running tangential to the rim of the merry-go-round at 3.99 m/s jumps onto its rim and holds on. Before jumping on the merry-go-round, the person was moving in the same direction as the merry-go-round's rim. (a) Does the kinetic energy of the system increase, decrease, or stay the same when the person jumps on the merry-go-round? increase stay the same decrease (b) Calculate the initial and final kinetic energies for this system. Ki = kJ Kf = kJ 2. Relevant equations KErot= 1/2*Iw^2 I=1/2mr^2 3. The attempt at a solution a) I would think it should increase but im probably wrong, lol. b) The merry-go-round initially is just spinning so I trued finding the KE using the 1/2*I*w^2 formula so I got 1/4*m*r^2*w^2and I came up with 4.98 kJ and thats the wrong answer... is there something I did wrong? I don't have any idea how to find the KEf. Can I assume that its the rotational KE of the merry-goround plus the KE of the guy jumping on it?