Moment of inertia of a plate,is `40 kgm^2`. How much work to be done to change its angular velocity from 60 rpm to 150 rpm.

Moment of inertia of a wheel is 0.004 kg. m^(2) . If its number of revolutions is increased from 60 rpm to 150 rpm in 3 s, determine the magnitude of the torque acting on it.

Moment of inertia of a disc is 100 g. cm^(2) . If the disc rotates with an angular velocity of 2 rad .s^(-1) the rotational kinetic energy of the disc is

An aritificial satellite of mass m is moving round the earth, in an orbit of radius 2R. How much work is to be done to transfer the satellite to an orbit of radius 4R? How will the potential energy of the satellite change? (R = Radius of earth).

An artificial satellite of mass m is moving round the earth in an orbit of radius 2R. How much work is to be done to transfer the satellite to an orbit of radius 4R ? How will the potential energy of the satellite change ? (R=Radius of earth)

If the moment of inertia of a body rotating about an axis is increased, state whether its angular velocity increases or decreases when no external torque acts on the body.