Two balls are projected upward simultaneously with speeds $40 \, m/s$ and $60 \, m/s$. The relative position $(x)$ of the second ball with respect to the first ball at time $t = 5 \, s$ is .......... $m$ [Neglect air resistance].

$A$ ball is dropped from the top of a building $100\,m$ high. At the same instant,another ball is thrown upwards with a velocity of $40\,m/s$ from the bottom of the building. The two balls will meet after $..........\,s$.

Two cars $A$ and $B$ are travelling in the same direction with velocities $v_1$ and $v_2$ $(v_1 > v_2)$. When car $A$ is at a distance $d$ ahead of car $B$,the driver of car $A$ applies the brake,producing a uniform retardation $a$. There will be no collision when:

Two cars are travelling towards each other at a speed of $20 \,m \,s^{-1}$ each. When the cars are $300 \,m$ apart, both the drivers apply brakes and the cars retard at the rate of $2 \,m \,s^{-2}$. The distance between them when they come to rest is: (in $\,m$)

$A$ body is projected vertically upward with speed $10 \, m/s$ and another at the same time with the same speed in the downward direction from the top of a tower. The magnitude of the acceleration of the first body with respect to the second is ...... $m/s^2$ (take $g = 10 \, m/s^2$).

$A$ bus is moving with a velocity $10\, ms^{-1}$ on a straight road. $A$ scooterist wishes to overtake the bus in $100\, s$. If the bus is at a distance of $1\, km$ from the scooterist,with what velocity should the scooterist chase the bus? ......... $ms^{-1}$