Two particles, one at the centre of a circle of radius $R$, and another at a point $Q$ on the circle, start moving towards a point $P$ on the circle at the same time (see figure below). Both are at rest initially and move with uniform velocities $\vec{V}_1$ and $\overrightarrow{V_2}$ respectively. They also reach the point $P$ at the same time, If the angle between the velocities is $\theta$ and the angle subtended by $P$ and $Q$ at the centre is $\phi$ (as shown in the figure), then
$\tan \frac{\phi}{2}=\cot \theta$
$\tan \phi=\cot \theta$
$\cot \frac{\phi}{2}=\cot \theta$
$\tan \frac{\phi}{2}=\cot \frac{\theta}{2}$
A particle moves in a circle of radius $25\, cm$ at two revolutions per second. The acceleration of the particle in $meter/second^2$ is
A stone of mass $1\,kg$ is tied to end of a massless string of length $1\,m$. If the breaking tension of the string is $400\,N$, then maximum linear velocity, the stone can have without breaking the string, while rotating in horizontal plane, is $.......\,ms^{-1}$
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 simple pendulum is oscillating without damping. When the displacement of the bob is less than maximum, its acceleration vector $\vec a$ is correctly shown in
$A \,10\, kg$ ball attached to the end of a rigid massless rod of length $1\, m$ rotates at constant speed in a horizontal circle of radius $0.5\, m$ and period $1.57 \, sec$ as in fig. The force exerted by rod on the ball is ........ $N$.