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Grade 12Thermal Physics

A metal sphere of radius 'r' and specific heat 's' is rotated about an axis paying through is centre at a speed of 'n' rotations. If it suddenly stops and 50% of its energy is used in increasing its temperature. The rise in temperature of sphere is

Profile image of Chaitanya
8 Years agoGrade 12
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1 Answer

Profile image of Arun
8 Years ago
A.T.Q 
It's rotational K.E. = n*m*(r^2)*pi / 5
So 50% energy = n*m*(r^2)*pi / 10
So that much energy is absorbed by sphere to increase it's temperature:
So
m*S*(del. T) = n*m*(r^2)*pi / 10
So del. T = n * r^2 *pi / (10*S)