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Physics NCERT Exemplar Solutions Class 12th Chapter Six Physics Class 12th Physics NCERT Exemplar Solutions Class 12th Chapter Five Laws of Motion

A thin circular ring of mass M and radius R is rotating with a constant angular velocity 2 rads^-1 in a horizontal plane about an axis vertical to its plane and passing through the centre of the ring. If two objects each of mass m be attached gently to the opposite ends of a diameter of ring, the will then rotate with an angular velocity (in rads^-1).

Option 1 -

$\frac{M}{(M + m)}$

Option 2 -

$\frac{(M + 2 m)}{2 M}$

Option 3 -

$\frac{2 M}{(M + 2 m)}$

Option 4 -

$\frac{2 (M + 2 m)}{M}$

2 Views | Posted 2 months ago

Asked by Shiksha User

1 Answer

Answered by

Payal Gupta | Contributor-Level 10

2 months ago

Correct Option - 3

Detailed Solution:

By conservation of Angular momentum

L_i = L_f

$M R^{2} ω = (m R^{2} + 2 m R^{2}) ω'$

$\frac{2 M}{M + 2 m} = ω'$

$\Rightarrow$ $ω' = \frac{2 M}{M + 2 m}$

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