Question

A stone of mass $0.5kg$ is attached to a string of length $2m$ and is whirled in a horizontal circle. If the string can with stand a tension of $9N$, the maximum velocity with which the stone can be whirled is:

• A. $6m{s}^{-1}$
• B. $8m{s}^{-1}$
• C. $4m{s}^{-1}$
• D. $12m{s}^{-1}$

Answer 1

The correct option is A $6m{s}^{-1}$

Given,

$Mass,M=0.5kg$

$Radius,R=2m$

$Tension,T=9N$

Centrifugal force = tension in string

$\frac{M{V}^2}{r}=T$

$V=\sqrt{\frac{Tr}{M}}=\sqrt{\frac{9\times 2}{0.5}}=6m{s}^{-1}$

Maximum velocity of stone is $6m{s}^{-1}$