A disc with moment of inertial I is rotating with some angular speed. Second disc is initially at rest. Now second disc with moment of inertia 3I is placed on first disc and starts rotating. Find loss of kinetic energy in fraction

A disc of moment of inertia I_(1) is rotating freely with angular speed omega_(1) when another non-rotating disc of moment of inertia I_(2) is dropped on it. The two discs then rotate as one unit. Find the final angular speed.

A disc with moment of inertia I_(1) , is rotating with an angular velocity omega_(1) about a fixed axis. Another coaxial disc with moment of inertia I_(2) , which is at rest is gently placed on the first disc along the axis. Due to friction discs slips against each other and after some time both disc start rotating with a common angular velocity. Find this common angular velocity.

A disc is rotating with angular speed omega_(1) . The combined moment of inertia of the disc and its axle is I_(1) . A second disc of moment of inertia I_(2) is dropped on to the first and ends up rotating with it. Find the angular velocity of the combination if the original angular velocity of the upper disc was (a) zero (b) omega_(2) in the same direction as omega_(1) and (c) omega_(2) in a direction opposite to omega_(1) .

A circular disc of moment of inertia I_(t) is rotating in a horizontal plane about its symmetry axis with a constant angular velocity omega_(i) . Another disc of moment of inertia I_(b) is dropped co-axially onto the rotating disc. Initially, the second disc has zero angular speed. Eventually, both the discs rotate with a constant angular speed omega_(f) . Calculate the energy lost by the initially rotating disc due to friction.

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 :

A disc of moment of inertia 4kgm^2 is spinning freely at 3rads^(-1) . A second disc of moment of inertia 2kgm^2 slides down the spindle and they rotate together. (a) What is the angular velocity of the combination ? (b) What is the change in kinetic energy of the system?