
A small mass attached to a string rotates on a frictionless tabletop as shown. If the tension in the string is increased by pulling the string causing the radius of the circular motion to decrease by a factor of , the kinetic energy of the mass will:-




Important Questions on Rotational Mechanics
is an equilateral triangle with as its centre. and represent three forces acting along the sides , and respectively. If the total torque about is zero then the magnitude of is:-



The moment of inertia of a uniform circular disc is maximum about an axis perpendicular to the disc and passing through:




A mass moves in a circle on a smooth horizontal plane with velocity at a radius . The mass is attached to a string which passes through a smooth hole in the plane as shown.
The tension in the string is increased gradually and finally moves in a circle of radius . The final value of the kinetic energy is:-
