Rotation And Revolution

A fly wheel of moment of inertia I is rotating at n revolutions per sec. The work needed to double the frequency would be -

Find torque required so that a coin of mass 1kg rotates 25 revolution in 5 sec starting from rest.

A rod of mass 1kg and length 6.25 m is hinged at one end of a smooth horizontal surface. A force of magnitude (pi)/(3)N acts it such that it is always perpendicular to the rod. Find the time (in sec.) when the rod has rotated one revolution?

A chain of 125 links is 1.25 m long and has mass of 2 kg with the ends fastened together. It is set for rotating at 50 revolutions per second. The centripetal force on each link is

A student peddles a stationary bicycle. The pedals are connected to a coil of 100 turns and area 0.1 m^(-2) . The coil is placed in a uniform magnetic field of 10^(-2) T , perpendicular to the axis of rotation of the coil. What is the maximum voltage generated in the coil if the coil rotates at 60 revolution per minute?

A table fan rotating at a speed of 2400 rpm is switched off and the resulating variation of the revolution/minute time is shown in Fig. The total number of revolutions of the fan before it comes to rest is