The spin dryer of a washing machine rotating at 15 r.p.slows down to 5 r.p.s. after making 50 revolutions. Find its angular acceleration.

A body starts rotating from rest and completes 10 revolutions in 4 s. Find its angular acceleration.

A gramophone twin-table rotating at an angular velocity 3frac(rad)(s) , stops after one revolution. Find the angular retardation.

A ring and a disc of different masses are rotating with the same kinetic energy. If we apply a retarding torque r on the ring and the ring stops after making n revolutions, then in how many revolutions will the disc stop under the same retarding torque ?

A coin just remains on a disc rotating at 120 r.p.m. when kept at the distance of 1.5 cm from the axis of rotation. Find the coefficient of friction between the coin and the disc.

A wheel having a diameter of 3 m starts from rest and accelerates uniformly to an angular velocity of 210 r.p.m. in 5 seconds. Angular acceleration of the wheel is

A needle of a sewing machine moves along a path of amplitude 4 cm with frequency 5 Hz . Find its acceleration [1/30] s after it has crossed the mean position.

A torque of 50 Nm acts on a rotating body for 5 s. Its angular momentum

A flywheel in the form of disc is rotating about an axis passing through its center and perpendicular to its plane looses 100J of energy , when slowing down from 60 r.p.m. to 30 r.p.m. Find its moment of inertia about the same axis and change in its angular momentum.

A flywheel rotating about an axis passing through its centre and at right angles to its plane losses 10 J of energy, when slowing down from 60 r.p.m. to 30 r.p.m. Find its M.I about the same axis. What is the change in its angular momentum ?