Rotational Motion Question 193
Question: A round disc of moment of inertia $I _{2}$ about its axis perpendicular to its plane and passing through its centre is placed over another disc of moment of inertia $I _{1}$ rotating with w angular velocity co about the same axis. The final angular velocity of the combination of discs is
Options:
A) $\frac{(I _{1}+I _{2})\omega }{I _{1}}$
B) $\frac{I _{2}\omega }{I _{1}+I _{2}}$
C) $\omega $
D) $\frac{I _{1}\omega }{I _{1}+I _{2}}$
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Answer:
Correct Answer: D
Solution:
[d] Angular momentum will be conserved
$I _{1}\omega =I _{1}\omega ‘+I _{2}\omega ‘\Rightarrow \omega ‘=\frac{I _{1}\omega }{I _{1}+I _{2}}$
