A wheel of radius $20\, cm$ has forces applied to it as shown in the figure. The net torque produced by the forces $4\, N$ at $A, 8\, N$ at $B, 6\, N$ at $C$ and $9\, N$ at $D$ at angles indicated is

Three bodies , a ring, a solid cylinder and a solid sphere roll down the same inclined  plane without slipping. They start from rest. The radii of the bodies are identical. Which  of the bodies reaches the ground with maximum velocity?

Which vector in the figures best represents the acceleration of a pendulum mass at the intermediate point in its swing?

A particle originally at rest at the highest point of $a$ smooth vertical circle is slightly displaced. It will leave the circle at $a$ vertical distance $h$ below the highest point, such that

A disc of mass $M$ and radius $R$ rolls on a horizontal surface and then rolls up an inclined plane as shown in the figure. If the velocity of the disc is $v,$ the height to which the disc will rise will be

The centre of mass of two masses $m$ and $m'$ moves by distance $\frac {x}{5}$ when mass $m$ is moved by distance $x$ and $m'$ is kept fixed. The ratio $\frac {m'}{m}$ is