A student skates up a ramp that makes an angle $30^{\circ}$ with the horizontal. $He /$ she starts (as shown in the figure) at the bottom of the ramp with speed $v_0$ and wants to turn around over a semicircular path xyz of radius $R$ during which he/she reaches a maximum height $h$ (at point y) from the ground as shown in the figure. Assume that the energy loss is negligible and the force required for this turn at the highest point is provided by his/her weight only. Then ( $g$ is the acceleration due to gravity)

$(A)$ $v_0^2-2 g h=\frac{1}{2} g R$

$(B)$ $v_0^2-2 g h=\frac{\sqrt{3}}{2} g R$

$(C)$ the centripetal force required at points $x$ and $z$ is zero

$(D)$ the centripetal force required is maximum at points $x$ and $z$

A particle moves with constant angular velocity in a circle. During the motion its

A particle moves in a circle of radius $25\,cm$ at two revolutions per sec. The acceleration of the particle in $m/s^2$ is

An object is moving in a circle of radius $100 \,m$ with a constant speed of $31.4 \,m/s$. What is its average speed for one complete revolution ......... $m/s$

A scooter is going round a circular road of radius $100 \,m$ at a speed of $10 \,m/s$. The angular speed of the scooter will be ......... $rad/s$

A huge circular arc of length $4.4$ $ly$ subtends an angle $'4 {s}'$ at the centre of the circle. How long it would take for a body to complete $4$ revolution if its speed is $8 \;AU\;per\, second \;?$

Given : $1\, {ly}=9.46 \times 10^{15} \,{m},$ $\, {AU}=1.5 \times 10^{11}\, {m}$