A ballet dancer spins about a vertical axis at 90 rpm with arms outstretched. With her arms folded, the M.I. about the axis of rotation decreases to 75%.Calculate the new rate of revolutions

A ballet dancer spins about a vertical axis at 90 rpm with arms outstretched. With the arms folded, the moment of inertia about the same axis of rotation changes to 75 %. Calculate the new speed of rotation.

Aballet dancer spins about a vertical axis at 120rpm with arms outstretched. With her arms folded the moment of inertia about the axis of rotation decreases by 40 %. What isnew rate of revolution ?

A ballet dancer spins about a vertical axis at 2.5pi rad s^-1 with his arms outstretched. With the arms folded, the M.I. about the same axis of rotation changes by 25%.Calculate the new speed of rotation in r.p.m.

A dancer spins about himself with an angular speed omega with his arms extended. When he draws his hands in, his moment of inertia reduces by 40%. Then his new angular velocity would be

A merry-go-round usually consists of a central vertical pillar. At the top of it there are horizontal rods which can rotate about vertical axis. At the end of this horizontal rod there is a vertical rod fitted like an elbow joint . At lower end of each vertical rod, There is a horse on which the rider can sit. As the merry-go-round is set into rotation, these vertical rods move away from the axis by making some angle with the vertical. The figure above shows vertical section of a merry go round in which the 'initially vertical ' rods are inclined with the vertical at 37^@ ,during rotation. Calculate the frequency of revolution of merry go round. (Use g=pi^2ms^-2 and sin37^@=0.6)

A horizontal disc is freely rotating about a vertcal axis passing through its centre at the rate of 125 r.p.m. A blob of wax of mass 50 gm falls on it and sticks to it at a distance of 10 cm from the axis. If the reslting frequency of rotation is 75 r.p.m, calculate the moment of inertia of the disc.

If the diameter of flywheel is increased by 1%, then increase in its M.I. about an axis passing through centre and perpendicular to the plane will be

A disc rotates horizontal at the rate of 100 rpm and M.I. of the disc about the axis of rotation is 1 kg m^2 . If a blob of molten wax weighing 50 gm drops gently at a distance 20 cm from the axis of rotation of the disc and remains stuck to it, then the increase in moment of inertia of the system will be