$A$ projectile crosses two walls of equal height $H$ symmetrically as shown in the figure. The time of flight $T$ is given by ........ $\text{s}$.

The second's hand of a watch has a length of $6\,cm$. The speed of the end point and the magnitude of the difference of velocities at two perpendicular positions will be:

$A$ car runs at a constant speed on a circular track of radius $100\,m$,taking $62.8\,s$ for every circular lap. The average velocity and average speed for each circular lap respectively are:

$A$ particle is moving such that its position coordinates $(x, y)$ are $(2 \, m, 3 \, m)$ at time $t = 0$,$(6 \, m, 7 \, m)$ at time $t = 2 \, s$,and $(13 \, m, 14 \, m)$ at $t = 5 \, s$. The average velocity vector $\vec{v}_{av}$ from $t = 0$ to $t = 5 \, s$ is:

Assertion $(A)$: When a vehicle takes a turn on the road,it travels along a curved path. Reason $(R)$: In a curved path,the velocity of the vehicle remains the same.

$A$ particle is moving with velocity $\vec v = K(y\hat i + x\hat j)$ where $K$ is a constant. The general equation for its path is