Two circular discs are made of the same material. The ratio of their radii is R1/R2 = 2. If their moments of inertia about their respective central axes are equal, the ratio of their thicknesses T1/T2 is given by 1/α. Find the value of α.

The angular speed of a flywheel is increased from 600 rpm to 1200 rpm in 10 s. The number of revolutions completed by the flywheel during this time is:

If F = 6î - 3ȷ + 2k̂ is a force acting on a point P whose position vector with respect to origin is r = 2î + ȷ - k̂, then the torque τ acting on the point is: