A disk with moment of inertia I₁ rotates about a frictionless, vertical a:de with angular speed $ω_{1}$ . A second disk, this one having moment of inertia l₂ and initially not rotating, drops onto the first disk (figure). Because of friction between the surfaces, the two eventually reach the same angular speed $ω_{f}$ . The value of $ω_{f}$ is

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

$\frac{I_{1}}{I_{2}} ω_{i}$

$\frac{I_{1}}{I_{1} + I_{2}} ω_{i}$

$\frac{I_{1} + I_{2}}{I_{1}} ω_{i}$

$\frac{I_{1} + I_{2}}{I_{2}} ω_{i}$

answer is B.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

From conservation of angular momentum for the isolated system of two disks:

$(I_{1} + I_{2}) ω_{f} = I_{1} ω_{i} or ω_{f} = \frac{I_{1}}{I_{1} + I_{2}} ω_{i}$

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE