A man walks on a straight road from his home to a market $2.5\; km$ away with a speed of $5 \;km h ^{-1} .$ Finding the market closed, he instantly turns and walks back home with a speed of $7.5 \;km h ^{-1} .$ What is the magnitude of average velocity in $m/s$?

A point traversed $3 / 4$ th of the circle of radius $R$ in time $t$. The magnitude of the average velocity of the particle in this time interval is

A particle covers half of its total distance with speed $v_1$ and the rest half distance with speed $v_2 .$ Its average speed during the complete journey is 

Define velocity. Define average velocity.

Figure gives the $x-t$ plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest, and in which is it the least ? Give the sign of average velocity for each interval.

A car moves from $X$ to $Y$ with a uniform speed $v_1$ and returns to $Y$ with a uniform speed $v_2$ . The average speed for this round trip is