29.A circular disc is rotating with angular velocity
If a man standing at the edge of the dise walks
towards its centre, then the angular velocity of the
disc:
a. is not changed
b. be halved
c. decreased
d. increased
Answers
Answered by
1
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 l is moment of inertia of the body and ω is angular velocity.
Also l=
2
1
MR
2
(for disc) where M is mass and R is radius of disc.
J=
2
1
MR
2
ω= constant
Since, man moves towards the centre of the disc, distance of mass distribution R decreases hence, ω increases.
From law of conservation of angular momentum, we have
J=lω=constant
where l is moment of inertia of the body and ω is angular velocity.
Also l=
2
1
MR
2
(for disc) where M is mass and R is radius of disc.
J=
2
1
MR
2
ω= constant
Since, man moves towards the centre of the disc, distance of mass distribution R decreases hence, ω increases.
Similar questions