Question

A ballerina spinning at 1.2 rev/sec with a moment of inertia of 2.6 kgm2 pulls her arms in so that her new moment of inertia is 1.8 kgm2. What is her new angular speed?

Answer 1

`10,891 rad//s`

Explanation:

Using the Principle of Conservation of Angular Momentum, we get :

`L_1 = L_2`
`therefore I_1omega_1=I_2omega_2`
`therefore omega_2=(I_1omega_1)/(I_2)=((2,6kg.m^2)(7,54rad//s))/(1,8kg.m^2)=10,891 rad//s`