Hey thanks for the help doc, I got it...feel so stupid for asking as the solution was like 3 lines long. And yea there is no conservation of energy as the next question was to find out the mechanical energy lost to friction !
The Question:
A 45kg child runs at 3.0m/s and jumps tangentially onto a stationary merry-go-round. The moment of inertia of the merry-go-round is 360 kgm^2 and the radius is 2.0m. What is the angular velocity of the child and the merry-go-round?
My attempts:
I'm not sure how to...