What is rotational motion and  axis ?  

Which types of force acting on the system of particle ?

A cylinder of mass $M$ and radius $r$ is mounted on a frictionless axle over a well. A rope of negligible mass is wrapped around the cylinder and a bucket of mass $m$ is suspended from the rope. The linear acceleration of the bucket will be

Let $\mathop A\limits^ \to  $ be a unit vector along the axis of rotation of a purely rotating body and $\mathop B\limits^ \to  $ be a unit vector along the velocity of a particle $ P$ of the body away from the axis. The value of $\mathop A\limits^ \to  .\mathop B\limits^ \to  $ is

There is a rod of lenght $l$, mass $m$ lying on a fixed horizontal smooth table. A cord is led through a pulley, and its horizontal part is attached to one end of the rod, while its vertical part is attached to a block of mass $m_1$.  Assume pulley and the cord is ideal. The maximum possible acceleration of the rod's centre of mass $C$ (for all possible values of masses $m$ and $m_1$) at the moment of releasing the block $m_1$ is $\frac{g}{n}$.  Find the value of $n$

Fly-wheel is used with an engine because it