A stone of mass $m$ is tied to a string and is moved in a vertical circle of radius $r$ making $n$ revolutions per minute. The total tension in the string when the stone is at its lowest point is 

$A$ small cube with mass $M$ starts at rest at point $1$ at a height $4R$, where $R$ is the radius of the circular part of the track. The cube slides down the frictionless track and around the loop. The force that the track exerts on the cube at point $2$ is nearly ……… times the cube's weight $mg$.

The bob of a simple pendulum is displaced from its equilibrium position $O$ to a position $Q$ which is at height $h$ above $O$ and the bob is then released. Assuming the mass of the bob to be $m$ and time period of oscillations to be $2.0\  s$, the tension in the string when the bob passes through $O$ is

A particle of mass $m$ is tied to string of length $l$ and whirled in vertical circle. The difference of tension and kinetic energy at highest and lowest position of circular path will be

A mass $m$ is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when