If frictional force is neglected and girl bends her hand, then (initially girl is rotating on chair)

Question

If frictional force is neglected and girl bends her hand, then (initially girl is rotating on chair) (A) I text girl will reduce (B) I text girl will increase (C) ω text girl will reduce (D) None of the above

Tardigrade Admin · Accepted Answer

As there is no external torque, so if the girl bends her hands, her moment of inertia about the rotational axis will decrease. By conservation of angular momentum, L=I ω= constant. So in order to keep L constant, if I is decreasing, then ω will increase.

Q. If frictional force is neglected and girl bends her hand, then (initially girl is rotating on chair)

$I_{girl}$ will reduce

$I_{girl}$ will increase

$ω_{girl}$ will reduce

None of the above

As there is no external torque, so if the girl bends her hands, her moment of inertia about the rotational axis will decrease. By conservation of angular momentum, $L = I ω =$ constant. So in order to keep $L$ constant, if $I$ is decreasing, then $ω$ will increase.

Q. If frictional force is neglected and girl bends her hand, then (initially girl is rotating on chair)

Igirl ​ will reduce

Igirl ​ will increase

ωgirl ​ will reduce

None of the above

As there is no external torque, so if the girl bends her hands, her moment of inertia about the rotational axis will decrease. By conservation of angular momentum, L=Iω= constant. So in order to keep L constant, if I is decreasing, then ω will increase.

$I_{girl}$ will reduce

$I_{girl}$ will increase

$ω_{girl}$ will reduce

As there is no external torque, so if the girl bends her hands, her moment of inertia about the rotational axis will decrease. By conservation of angular momentum, $L = I ω =$ constant. So in order to keep $L$ constant, if $I$ is decreasing, then $ω$ will increase.