Physics
posted by tiffany
A 3.6 m diameter merrygoround is rotating freely with an angular velocity of 0.78 rad/s. Its total moment of inertia is 1700 kg m^2. Four people standing on the ground, each of mass 62 kg, suddenly step onto the edge of the merrygoround.
What is the angular velocity of the merrygoround now?
Express your answer using two significant figures.
What if the people were on it initially and then jumped off in a radial direction (relative to the merrygoround)?

bobpursley
When they step on, the I increases by 4*62*1.8^2 (mr^2)
so, wnew=wold* Iold/Inew
In the second case, Inew would be decreased, ..
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