Answer:
Explanation:
In a rotating system , when a torque is applied , angular acceleration or deceleration takes place . The child is walking towards the center . He must be applying force on the ground . In return , ground must be applying reaction force on him which helps him to go towards the center . These two force of action and reaction are internal forces . One will increase the angular momentum of one and the other force will decrease the angular
momentum of other . But total angular momentum of the whole system will remain constant . So angular momentum will be conserved.
