A particle is released on a vertical smooth semicircular track from point $X$ so that $OX$ makes angle $\theta $ from the vertical ( see figure). The normal reaction of the track on the particle vanishes at point $Y$ where $OY$ makes angle $\phi $ with the horizontal. Then
$\sin \,\phi = \,\cos \,\phi $
$\sin \,\phi = \frac{1}{2}\,\cos \,\theta $
$\sin \,\phi = \frac{2}{3}\,\cos \,\theta $
$\sin \,\phi = \frac{3}{4}\,\cos \,\theta $
A man carrying a monkey on his shoulder does cycling smoothly on a circular track of radius $9 \mathrm{~m}$ and completes $120$ revolutions in $3$ minutes. The magnitude of centripetal acceleration of monkey is (in $\mathrm{m} / \mathrm{s}^2$ ):
Two spheres $P$ and $Q$ of equal masses are attached to a string of length $2\,\, m$ as shown in figure. The string and the spheres are then whirled in a horizontal circle about $O$ at a constant rate. What is the value of the ratio
$\left( {\frac{{{\text{Tension in the string between P and Q}}}}{{{\text{Tension in the string between P and O}}}}} \right)?$
A ball is moving uniformly in a circular path of radius $1 m$ with a time period of $1.5 \,s$. If the ball is suddenly stopped at $t=8.3 \,s$, the magnitude of the displacement of the ball with respect to its position at $t=0 \,s$ is closest to .......... $m$
A particle is moving on a circular path of radius $r$ with uniform speed $v$. The magnitude of change in velocity when the particle moves from $P$ to $Q$ is $(\angle POQ = 40^o)$
An object moves at a constant speed along a circular path in a horizontal plane with centre at the origin. When the object is at $x =+2\,m$, its velocity is $-4 \hat{ j }\, m / s$. The object's velocity $(v)$ and acceleration $(a)$ at $x =-2\,m$ will be