A stone tied to the end of a string of $1\, m$ long is whirled in a horizontal circle with a constant speed. If the stone makes $22$ revolution in $44\, seconds$, what is the magnitude and direction of acceleration of the stone?
${\pi ^2}\,m\,{s^{ - 2}}$ and direction along the radius towards the centre
${\pi ^2}\,m\,{s^{ - 2}}$ and direction along the radius away from the centre
${\pi ^2}\,m\,{s^{ - 2}}$ and direction along the tangent to the circle.
${\pi ^2}/4\,m\,{s^{ - 2}}$ and direction along the radius towards the centre.
A proton of mass $ 1.6 \times 10^{-27} kg$ goes round in a circular orbit of radius $0.10\, m$ under a centripetal force of $4 \times 10^{-13}\, N$. then the frequency of revolution of the proton is about
Certain neutron stars are believed to be rotating at about $1\,rev/\sec $. If such a star has a radius of $ 20\, km$, the acceleration of an object on the equator of the star will be
Two particles each of mass $m$ are moving in horizontal circle with same angular speed. If both string are of same length then the ratio of tension in string $\frac{T_1}{T_2}$ is .........
Check up the only correct statement in the following :-
A train is moving towards north. At one place it turns towards north-east, here we observe that