Lesson: Conservation of Angular MomentumPhysics
In this lesson, we will learn how to calculate the variation of the moment of inertia of a rotating body with its angular velocity.
Sample Question Videos
Three children are riding on the edge of a merry-go-round that has a mass of 100.0 kg and a radius of 1.60 m and is spinning at 20.0 rpm. The children have masses of 22.0 kg, 28.0 kg, and 33.0 kg. If the child who has a mass of 28.0 kg moves to the center of the merry-go-round, what is the new angular velocity in revolutions per minute?
Eight children, each of mass 40 kg, climb on a small merry-go-round. They position themselves evenly on the outer edge and join hands. The merry-go-round has a radius of 4.0 m and a moment of inertia 1,000.0 kg⋅m2. After the merry-go-round is given an angular velocity of 6.0 rpm, the children walk inward and stop when they are 0.75 m from the axis of rotation. What is the new angular velocity of the merry-go-round? Assume there is negligible frictional torque on the structure.
A merry-go-round has a radius of 2.0 m and a moment of inertia 300 kg⋅m2. A boy of mass 50 kg runs tangent to the rim at a speed of 4.0 m/s and jumps on. If the merry-go-round is initially at rest, what is the angular velocity after the boy jumps on?