Question

equipment. A 3.0-m-diameter merry-go-round with a mass of 300 kg is spinning at 15 rpm . John runs tangent to the merry-go-round at 4.8 m/s , in the same direction that it is turning, and jumps onto the outer edge. John's mass is 30 kg.

Part A: What is the merry-go-round's angular velocity, in rpm, after John jumps on?

Answer 1

Use the law of conservation of angular momentum to find the angular velocity: Here, Liis the initial angular momentum and L, is the final angular momentum. The moment of inertia of the disc is, (300kg (1.5m) -337.5kg-m2 The initial angular momentumof the systemis, k0k)4m m) (337.5kg-m)(15rpm) 745.87kg-m'/s +(30kg)(4.8m/s)(1.5m) 1 rev 60s The final angular momentum of the systemis, | (337. 5 kg-m2)4(30kg)(1.5m)2 |d, [405kg-m'/s a The angular velocity is 745.87 kg-m2/s-(405 kg-m2/s]o, a, = 1.84 rad/ s 17.59 1pm