# Physics

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A hollow sphere of radius 25 cm is rotating at 13 rad/ sec about an axis that passes through its center. The mass of the sphere is 3.8 kg. assuming a constant net torque is applied to the sphere, how much work is required to bring the sphere to a stop?

• Physics -

Just to comment, I'm not trying to hw dump like the person underneath me. If someone can help me get started I can usually finish

• Physics -

The work required to get it to stop is minus the initial kinetic energy,
-(1/2) I w^2

w = 13 rad/s in this case.
I is the moment of inertia, which for a hollow sphere of mass M and radius R is
I = (2/3)M*R^2

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