$A$ train has a speed of $60\, km/h$ for the first one hour and $40\, km/h$ for the next half hour. Its average speed in $km/h$ is

$A$ car travels a distance $S$ on a straight road in two hours and then returns to the starting point in the next three hours. Its average velocity is

$A$ vehicle travels half the distance with speed $v$ and the remaining distance with speed $2v$. Its average speed is:

$A$ car covers the first half of the distance between two places at $40 \text{ km/h}$ and the second half at $50 \text{ km/h}$. The average speed of the car is (in $text{ km/h}$)

Give the difference between average speed and average velocity.

$A$ particle travels half of the distance of a straight journey with a speed $6 \,m/s$. The remaining part of the distance is covered with speed $2 \,m/s$ for half of the time of the remaining journey and with speed $4 \,m/s$ for the other half of the time. The average speed of the particle is ....... $m/s$.