$A$ train of $150 \ m$ length is going towards the north direction at a speed of $10 \ m/s$. $A$ parrot flies at a speed of $5 \ m/s$ towards the south direction parallel to the railway track. The time taken by the parrot to cross the train is........$s$.

$A$ bird is flying to and fro between two cars moving towards each other on a straight road. One car has a speed of $18\,km/h$ while the other has a speed of $27\,km/h$. The bird starts moving from the first car towards the other with a speed of $36\,km/h$. If the two cars were initially separated by $36\,km$,what is the total distance covered by the bird?

$A$ swimmer can swim with a velocity of $12 \, km/h$ in still water. The water flowing in a river has a velocity of $6 \, km/h$. The angle with respect to the direction of flow of the river water at which the swimmer should swim in order to reach the point on the other bank just opposite to his starting point is ........$^{\circ}$. (Round off to the Nearest Integer)

Explain this common observation clearly: If you look out of the window of a fast-moving train,the nearby trees,houses,etc.,seem to move rapidly in a direction opposite to the train's motion,but the distant objects (hilltops,the Moon,the stars,etc.) seem to be stationary. (In fact,since you are aware that you are moving,these distant objects seem to move with you).

$A$ train of $150 \,m$ length is going towards north direction at a speed of $10 \,ms^{-1}$. $A$ parrot flies at the speed of $5 \,ms^{-1}$ towards south direction parallel to the railway track. The time for which the parrot flies alongside the train is (in $\,s$)

$A$ motorboat is racing towards north at $25\; km/h$ and the water current in that region is $10\; km/h$ in the direction of $60^{\circ}$ east of south. Find the resultant velocity of the boat.