An inextensible string passing over a smooth pulley connects two blocks of masses $m_1$ and $m_2$ ($m_2 > m_1$) vertically. If the acceleration of the system is $\left(\dfrac{g}{n}\right)$, then the ratio of masses $\left(\dfrac{m_2}{m_1}\right)$ is

Given identical rings are arranged in a hexagonal plane pattern so as to touch each neighbouring ring as shown in figure. Each ring has mass M and radius R. The moment of inertia of the system of seven rings about an axis passing through the centre of central ring and normal to plane of all rings is

A kathak dancer is standing on horizontal surface with folded hands. In the begining dancer is rotating about his central axis and his kinetic energy is 'K' at that time. The kathak dancer now stretches his arms so that the moment of inertia of the dancer becomes three times and the angular velocity becomes one-third. The kinetic energy of the dancer now is

A solid sphere rolls without slipping on an inclied plane at an angle $\theta$. The ratio of total kinetic energy to its rotational kinetic energy is