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A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is . The child stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is

a)

b)

c)

d)


Question ID - 100212 | SaraNextGen Answer

A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is . The child stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is

a)

b)

c)

d)

1 Answer - 5876 Votes

3537

Answer Key : (b) -

(b)

From conservation of angular momentum ( = constant), angular velocity will remain half. As,

The rotational kinetic energy will become half.



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