A child is standing with his two arms outstretched at the centre of a turntable that is rotating about its central axis with an angular speed . Now, the child folds his hands back so that moment of inertia becomes 3 times the initial value. The new angular speed is
A
3 
B
C
D
Text Solution
Verified by ExpertsThe correct answer is:
B
: Here, Initial angular spped, 
Initial moment ofj inertia, = 
Final moment of inertia, 
According to the law of conservation of angular momentum, we get,
( 
)
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