QNEET-2013-Ph-1580: NEET 2013 Physics - Class 11 NEET-2013-Ph-1580 Solution: Two discs are rotating about their axes normal to the discs and …

Two discs are rotating about their axes normal to the discs and passing through the centres of the discs. Disc $D_1$ has 2 kg mass and 0.2 m radius and initial angular velocity of $50\ \text{rad s}^{-1}$. Disc $D_2$ has 4 kg mass 0.1 m radius and initial angular velocity of $200\ \text{rad s}^{-1}$. The two discs are brought in contact face to face with their axes of rotation coincident. The final angular velocity (in $\text{rad s}^{-1}$) of the system is 120 40 60 100