A particle moves in a circular path of radius $r$ with speed $v.$ It then increases its speed to $2\,v$ while travelling along the same circular path. The centripetal acceleration of the particle has changed by a factor of
$0.25$
$0.5$
$2$
$4$
A stone tied to $180 cm$ long string at its end is making 28 revolutions in horizontal circle in every minute. The magnitude of acceleration of stone is $\frac{1936}{ x }\,ms ^{-2}$. The value of $x.........\left(\text { Take } \pi=\frac{22}{7}\right)$
An electric fan has blades of length $30 \,cm$ as measured from the axis of rotation. If the fan is rotating at $1200\,$ r.p.m. , the acceleration of a point on the tip of the blade is about .......... $m/sec^2$
A particle of mass ${m}$ is suspended from a ceiling through a string of length $L$. The particle moves in a horizontal circle of radius $r$ such that ${r}=\frac{{L}}{\sqrt{2}}$. The speed of particle will be:
A wheel is rotating at $900\, r.p.m.$ about its axis. When the power is cut-off, it comes to rest in $1\,minute$ . The angular retardation in $radian/s^2$ is:-
A particle is moving on a circular path of radius $r$ with uniform speed $v$. What is the displacement of the particle after it has described an angle of $60^o$ ?