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  ........ $cm$

A particle moves in a circular path of radius $r$ with speed $v.$ It then increases its speed to $2\,v$ while travelling along the same circular path. The centripetal acceleration of the particle has changed by a factor of

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 ..........

Figure below shows a body of mass $M$ moving with the uniform speed on a circular path of radius, $R$. What is the change in acceleration in going from ${P_1}$ to ${P_2}$

A particle revolves round a circular path. The acceleration of the particle is

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