Question

A disk of mass M, radius R is rotating about an axis passing through its centre and perpendicular to its plane with angular speed ω. If another disk of mass $\frac{M}{2}$ and radius R is gently placed over it what will be their common angular velocity after some time?

• A. $\frac{ω}{5}$
• B. $\frac{ω}{2}$
• C. $\frac{2ω}{3}$
• D. $\frac{ω}{4}$

Answer 1

Answer: (C)

$\frac{2ω}{3}$

Answer 2

The Correct answer is option is (C) : $\frac{2ω}{3}$