Two uniform circular rough disc of moment of inertia `I_(1)` and `(I_(1))/(2)` are rotating with angular velocity `omega_(1)` and `(omega_(1))/(2)` respectively in same direction. Now one disc is placed the other disc co-axially. The change in kinetic energy of the system is :

Two discs of moments of inertia I_1 and I_2 about their respective axes , rotating with angular frequencies omega_1 and omega_2 respectively, are brought into contact face to face with their axes of rotation coincident. The angular frequency of the composite disc will be

Two discs of moments of inertia I_1 and I_2 about their respective axes, rotating with angular frequencies, omega_1 and omega_2 respectively, are brought into contact face to face with their axes of rotation coincident. The angular frequency of the composite disc will be A .

Two discs A and B are in contact and rotating with angular velocity with angular velocities omega_(1) and omega_(2) respectively as shown. If there is no slipping between the discs, then

Two discs A and B are in contact and rotating with angular velocity with angular velocities omega_(1) and omega_(2) respectively as shown. If there is no slipping between the discs, then

A uniform circular disc of radius R, lying on a frictionless horizontal plane is rotating with an angular velocity omega about is its own axis. Another identical circular disc is gently placed on the top of the first disc coaxially. The loss in rotational kinetic energy due to friction between the two discs, as they acquire common angular velocity is (I is moment of inertia of the disc)