Respuesta :
Answer:
f'=w'/2p=2.49rev/s
Explanation:
The angular momentum L must be equal for both cases.
Hence you have that
L before = L after
[tex]L=I\omega[/tex]
[tex]\omega=2\pi f[/tex]
I = moment of inertia
w =angular momentum
Hence
[tex]L=L'\\I\omega =I'\omega'\\\omega'=\frac{I\omega}{I'}=\frac{I*2\pi *1}{0.4I}=15.70\frac{rad}{s}[/tex]
f'=w'/2p=2.49rev/s
hope this helps!!