A 5.0-m radius playground merry-go-round (a solid disk) with a mass of 160 kg is rotating freely with an angular speed of 1.0 rad/s. Two people, each of mass 60 kg, are standing right outside the edge of the merry-go-round and suddenly step onto the edge with negligible speed relative to the ground. Though numbers are given, calculations are welcomed but not required for this problem. (10 points)

(a) How does the total angular momentum of the system change from before the people step on to after? Increase, decrease, stay the same? Give you reasoning.
 

(b) How does the angular speed of the merry-go-round change after the two people have stepped on? Increase, decrease, or stay the same? Give you reasoning.

Answer rating: 100% (QA)

a Angular Momentum Change The total angular momentum of the system decreases when the people step onto the merrygoround Heres why Initially The merrygoround is rotating and the people are not Therefore the system has the total angular momentum of the spinning merrygoround which is a nonzero value After When the people step onto the edge their initial angular momentum zero because they werent moving gets added to the system However since they are farther away from the center of rotation compared to their initial position their individual contribution to the total angular momentum is larger despite having zero initial momentum Adding this larger contribution due to increased distance from the center to the initial nonzero angular momentum of the merrygoround results in a net decrease in the total angular momentum of the system b Angular Speed Change The angular speed of the merrygoround decreases after the people step on ... View the full answer