Question 17 of 17 Map Openstax College Physics Openstax presented by Sapling Lea

Question

Question 17 of 17 Map Openstax College Physics Openstax presented by Sapling Learning Three children are riding on the edge of a merry-go-round that is 105 kg, has a 1.80-m radius, and is spinning at 16.0 rpm. The children have masses of 22.0, 28.0, 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 rpm? Ignore friction, and assume that the merry-go-round can be treated as a solid disk and the children as points Number rpm

Explanation / Answer

mass of the merry go round plat form M = 105 kg

radius r = 1.80m

Moment of inertia of the plat form Ip = 0.5 M r2 = 0.5 x 105 x 1.8 x 1.8 = 170.1 Kg-m2

Initial moment of inertia of the children Ic = mr2 = (22 + 28 + 33) x 1.8 x 1.8 = 268.9 Kg-m2

hence total initial moment of inertia Ii = 170.1 + 268.9 = 439 kg m2

final momen of inertia of the children = (22 + 33) x 1.8 x 1.8 = 178.2Kg-m2

total final moent of inertia = 170.1 + 178.2 = 348.3 Kgm2

from conser vation of angular momentum

Iiwi = Ifwf

wf = Iiwi / If = 439 x 16 / 348.3 = 20.17 rpm

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.