$A$ body of mass $m \ kg$ is rotating in a vertical circle at the end of a string of length $r \ m$. What is the difference in the kinetic energy at the top and the bottom of the circle?

$A$ stone tied to a string of length $L$ is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has a speed $u$. The magnitude of the change in its velocity, as it reaches a position where the string is horizontal, is $\sqrt{x(u^{2}-gL)}$. The value of $x$ is .............

If a particle completes a vertical circular motion,what is the ratio of its velocities at points $A$,$B$,and $C$?

Consider a particle moving with a minimum speed $v$ at the highest point of a vertical circle of radius $R$. If the radius of the circle is doubled,the corresponding minimum speed will be:

$A$ stone is tied to a string of length $L$ and is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has a speed $u$. The magnitude of the change in its velocity as it reaches a position where the string is horizontal is

$A$ mass $m$ is released from point $A$ as shown in the figure. The tension in the string at point $B$ will be: