A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is

A small object of uniform density rolls up a curved surface with an initial velocity 'v'. It reaches upto a maximum height of $${{3{v^2}} \over {4g}}$$ with respect to the initial position. The object is

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

A car of mass m is moving on a level circular track of radius R. If $$\mu $$_s represents the static friction between the road and tyres of the car, the maximum speed of the car in circular motion is given by