stone is tied to one end of a string $50\, cm$ long is whirled in a horizontal circle with a constant speed. If the stone makes $10$ revolutions in $20\, s$, what is the magnitude of acceleration of the stone ......... $cm/s^2$

A tube of length $L$ is filled completely with an incompressible liquid of mass $M$ and closed at both the ends. The tube is then rotated in a horizontal plane about one of its ends with a uniform angular velocity $\omega $. The force exerted by the liquid at the other end is

If a particle moves in a circle describing equal angles in equal times, its velocity vector

Four particles $A, B, C$ and $D$ are moving with constant speed $v$ each. At the instant shown relative velocity of $A$ with respect to $B, C$ and $D$ are in directions

A car is moving at a speed of $40 \,m / s$ on a circular track of radius $400 \,m$. This speed is increasing at the rate of $3 \,m / s ^2$. The acceleration of car is ....... $m / s ^2$

The linear speed of the tip of seconds hand of a wall clock is $1.05\,cm\,s^{-1}.$ The length of the seconds hand is nearly  ........ $cm$