The system of nine small 3 kg objects is rotating at an angular speed of 6 rev/s. The objects are connected by light, flexible spokes that can be lengthened or shortened.

Question

What is the new angular speed if the spokes are shortened from 6 m to 2 m?

Answer 1

conservation of angular momentum applies
Itotal*w=I'total*w'

but I' is changed by deltar^2, or (1/3)^2

w'=worig*9