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 ball of mass $0.1$ kg is suspended by a string. It is displaced through an angle of ${60^o}$ and left. When the ball passes through the mean position, the tension in the string is ........ $N$
$Assertion$ : When a particle moves in a circle with a uniform speed, its velocity and acceleration both changes.
$Reason$ : The centripetal acceleration in circular motion is dependent on angular velocity of the body.
A body is moving on a circle of radius $80 \,m$ with a speed $20 \,m / s$ which is decreasing at the rate $5 \,m / s ^2$ at an instant. The angle made by its acceleration with its velocity is ..........
A ball of mass $( m )=0.5 \ kg$ is attached to the end of a string having length $(L)$ $=0.5 m$. The ball is rotated on a horizontal circular path about vertical axis. The maximum tension that the string can bear is $324 \ N$. The maximum possible value of angular velocity of ball (in radian/s) is
When a body moves with a constant speed along a circle