Manipal Entrance Test 2013 Physics Paper

When no external force acts on a body its angular moment remains conserved.
From law of conservation of angular momentum, we have
J = lω = constant
where I is moment of inertia of the body and ω is angular velocity.
Also I=

1

2

MP2 (for disc) where M is mass and R is radius of disc.
J=

1

2

MR2ω− constant
Since, man moves towards the centre of the disc, distance of mass distribution R decreases hence, co increases.