Two coaxial discs, having moments of inertia $I_1$ and $\frac{I_1}{2}$ are a rotating with respectively angular velocities $\omega_1$ and $\frac{\omega_1}{2}$, about their common axes. They are brought in contact with each other and thereafter they rotate with a common angular velocity. If $E_f$ and $E_i$ are the final and initial total energies, then $(E_f -E_i)$ is
Two coaxial discs, having moments of inertia $I_1$ and $\frac{I_1}{2}$ are a rotating with respectively angular velocities $\omega_1$ and $\frac{\omega_1}{2}$, about their common axes. They are brought in contact with each other and thereafter they rotate with a common angular velocity. If $E_f$ and $E_i$ are the final and initial total energies, then $(E_f -E_i)$ is
- [JEE MAIN 2019]
- A
$\frac{{{I_1}\omega _1^2}}{6}$
- B
$\frac{3}{8}{I_1}\omega _1^2$
- C
$ - \frac{{{I_1}\omega _1^2}}{{12}}$
- D
$ - \frac{{{I_1}\omega _1^2}}{{24}}$
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