Question

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities ω1 and ω2. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is

• A. $\frac 12l(ω_1+ω_2)^2$
• B. $\frac 14l(ω_1-ω_2)^2$
• C. $l(ω_1-ω_2)^2$
• D. $\frac 18(ω_1-ω_2)^2$

Answer 1

Answer: (B)

$\frac 14l(ω_1-ω_2)^2$

Answer 2

The correct option is (B): $\frac 14l(ω_1-ω_2)^2$.