A child is standing in the center of a rotating playground p

A child is standing in the center of a rotating playground platform. What will happen if she makes her way from the center to the edge, assuming no net torque acts on the child + platform system ? The system\'s total rotational inertia the system\'s angular momentum be system\'s angular speed

Solution

as no torque acting on the child + platform system => angular momentum of this system is conserved

=> I1W1 = I2W2

as child goes to edge => R increases => I2 ( = mR^2) increases

=> W2 decreases

=> moment of inertia .....increases ( I)

angualr momentum ....doesn\'t change ( I*W)

angular speed .... decreases ( W)