Question

a stone of mass 0.5 kg is attached to the string of length 2 metre and is whirled in a horizontal circle if the string can withstand a tension of 9 Newton the maximum velocity with which stone can be world is​

Answer 1

Here the stone is in horizontal circular motion.

Since it is, the stone will attain a centripetal force which is completely provided by the tension in the string, i.e.,

$T=\dfrac {mv^2}{r}\\\\\\v=\sqrt {\dfrac {Tr}{m}}$

Then, we are given,

$T=9\ N\\\\r=2\ m\\\\m=0.5\ kg$

Hence,

$v=\sqrt {\dfrac {9\times 2}{0.5}}\\\\\\v=\mathbf {6\ ms^{-1}}$