Two particles held at different heights $a$ and $b$ above the ground are allowed to fall from rest. The ratio of their velocities on reaching the ground is,

In the displacement-time graph of a moving particle shown, the instantaneous velocity of the particle is negative at the point is,

The variation of velocity of a particle moving along a straight line is shown in the figure. The distance travelled by the particle in $4 \mathrm{s}$ is,

The displacement-time graphs of two particles $A$ and $B$ are straight lines making angles of respectively $30°$ and $60°$ with the time axis. If the velocity of $A$ is $v_A$ and that of $B$ is $v_B$, then the value of $\frac{v_A}{v_B}$ is?

Starting from rest at $t=0,$ a car moves in a straight line with an acceleration given by the accompanying graph. The speed of the car at $t=3 \mathrm{s}$ is,

In the one-dimensional motion of a particle, the relation between position $x$ and time $t$ is given by $x^2+2x=t$ (Here $x>0$). Choose the correct statement.

Two balls of equal masses are thrown upward, along the same vertical line at an interval of $2 \mathrm{seconds}$, with the same initial velocity of $40 \mathrm{m} {\mathrm{s}}^{-1}$. Then these collide at a height of (Take $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)