A solid disc of radius 20   cm and mass 10   kg is rotating with an angular velocity of 600  …

A solid disc of radius 20 cm and mass 10 kg is rotating with an angular velocity of 600 rpm, about an axis normal to its circular plane and passing through its centre of mass. The retarding torque required to bring the disc at rest in 10 s is _________π×10-1 N m

Solution

τ=ΔLΔt=Iωf-ωiΔt

τ=mR22×[0-ω]Δt

=10×20×10-222×600×π30×10

=0.4π=4π×10-1

Asked in: JEE Main 2021 (25 Jul Shift 2)

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