A disc rotated about its central axis and gently placed on another coaxial disc at rest. Due to friction between the two first disc retards and the second one starts rotating and after some time both with rotate with a common angular speed. In this process the total internal energy of the system of two discs does not change. State and justify whether this statement is true or false.

Two coaxial discs rotating in the same sense, stick to each other and spin with common angular speed. Find the loss in kinetic energy of the system?

A horizontal disc rotates freely about a vertical axis through its centre. A ring, having the same mass and radius as the disc, is now gently placed on the disc. After some time, the two rotate with a common angular velocity, then

A horizontal disc rotates freely with angular velocity omega about a vertical axes through its centre. A rig having the same mass and radius as the disc, is now gently placed coaxially on the disc. After some time, the two rotate with a common angular velocity. then.

Two identical discs are positioned on a vertical axis as shown in the figure. The bottom disc is rotating at angular velocity omega_(0) and has rotational kinetic energy K_(0) . Change in the rotational kinetic energy of the system is

A disc initially at rest , is rotated about its axis with uniform angular acceleration . In the first 2 s, it rotates an angle theta . In the next 2s, the disc rotates through an angle

A disc rotates about its axis with a constant angular acceleration of 4rad/s^2 . Find the radia and tangential acceleration of a particle at a distance of 1 cm from the axis at the end of the first second after the disc starts rotating.

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.

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, initially at rest, starts rotating about its own axis/ with a constant angular acceleration of 0*2 rad/s2. The time taken by the disc to rotate by 10 rad (in seconds) is

A uniform circulr disc of mass 200 g and radius 4.0 cm is rotated about one of its diameter at an angular speed of 10 rad/s. Find the knetic energy of the disc and its angular momentum about the axis of rotation.