Two cars get closer by $8\,m$ every second while travelling in the opposite directions. They get closer by $0.8\,m$ in every second while travelling in the same direction. What are the speeds of the two cars?

Car $A$ is moving to the East with a speed of $30 \text{ km/h}$,and car $B$ is moving to the North with the same speed. What is the velocity of car $B$ as measured from car $A$?

$A$ boat crosses a river with a velocity of $8 \, km/h$ relative to the water. If the resultant velocity of the boat with respect to the ground is $10 \, km/h$,then the velocity of the river water is...........$km/h$.

$A$ river has a steady speed of $v$. $A$ man swims upstream for a distance of $d$ and swims back to the starting point in a total time $t$. The man can swim at a speed of $2v$ in still water. If the time taken by the man in still water is $t_0$ to complete the same total distance of $2d$,then $\frac{t}{t_0}$ is

$A$ motorboat covers a given distance in $6 \,h$ moving downstream on a river. It covers the same distance in $10 \,h$ moving upstream. The time it takes to cover the same distance in still water is (in $\,h$)

On a two-lane road,car $A$ is travelling with a speed of $36 \; km/h$. Two cars $B$ and $C$ approach car $A$ in opposite directions with a speed of $54 \; km/h$ each. At a certain instant,when the distance $AB = AC = 1 \; km$,car $B$ decides to overtake car $A$ before car $C$ does. What minimum acceleration (in $m/s^2$) of car $B$ is required to avoid an accident?