$A$ boy walks to his school at a distance of $6\, km$ with a constant speed of $2.5\, km/h$ and walks back with a constant speed of $4\, km/h$. His average speed for the round trip,expressed in $km/h$,is:

$A$ particle moves with constant speed $v$ along a regular hexagon $ABCDEF$ in the same order. What is the magnitude of the average velocity for its motion from $A$ to $F$?

An object moves with speeds $v_1, v_2$,and $v_3$ along line segments $AB, BC$,and $CD$ respectively,as shown in the figure. If $AB = BC$ and $AD = 3 AB$,then the average speed of the object will be:

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

Which among average speed and average velocity can be positive,negative or zero?

$A$ person walks along a straight road from his house to a market $2.5 \,km$ away with a speed of $5 \,km/h$ and instantly turns back and reaches his house with a speed of $7.5 \,km/h$. The average speed of the person during the time interval $0$ to $50 \,min$ is (in $m/s$)