A solid sphere of mass 2 kg and radius 5 cm is rotating at the rate of 300 rpm. The torque required to stop it in `2pi` revolutions isA. `2.5 xx 10^(4) `dyne cmB. `2.5xx10^(-4)` dyne cmC. `2.5xx 10^(6)` dyne cmD. `2.5xx10^(5)` dyne cm

A solid sphere of mass 2 kg and radius 5 cm is rotating at the rate of

1.	A solid sphere of mass 2 kg and radius 5 cm is rotating at the rate of 300 rpm. The torque required to stop it in `2pi` revolutions isA. `2.5 xx 10^(4) `dyne cmB. `2.5xx10^(-4)` dyne cmC. `2.5xx 10^(6)` dyne cmD. `2.5xx10^(5)` dyne cm
Answer» Correct Answer - D In one revolution angle discribed is `2 pi` `therefore 2pi` revolution corresponds to `4 pi^(2)`. `tau = I alpha = ((2)/(5)MR^(2))((omega_(2)^(2)-omega_(1)^(2))/(2theta))` `= (2)/(5)xx2xx25xx10^(-4)xx(4pi^(2)(0-25))/(2xx4pi^(2))` `= 2.5xx10^(-2)Nm`. `= 2.5xx10^(-2)xx10^(7)` dyne cm.

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A solid sphere of mass 2 kg and radius 5 cm is rotating at the rate of 300 rpm. The torque required to stop it in `2pi` revolutions isA. `2.5 xx 10^(4) `dyne cmB. `2.5xx10^(-4)` dyne cmC. `2.5xx 10^(6)` dyne cmD. `2.5xx10^(5)` dyne cm

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