A uniform disc of mass 300 kg is rotating freely about a vertical axis through its centre at a constant angular velocity ω ° . A boy of mass 30 kg starts from the centre and moves along a radius to th

Question

A uniform disc of mass 300 kg is rotating freely about a vertical axis through its centre at a constant angular velocity ω ° . A boy of mass 30 kg starts from the centre and moves along a radius to the edge of the disc. Angular velocity of the disc will now become

TestHub · Accepted Answer

As Σ τ = 0 , angular momentum remains conseved: ∴ L = 0 + 300 R 2 2 ω 0 = 300 R 2 2 + 30 R 2 ω ⇒ 150 ω 0 = 180 ω ⇒ ω = 5 6 ω 0

Physics - Rotation Question with Solution | TestHub

Options:

Doubts & Discussion