$A$ car travels from $A$ to $B$ at a speed of $20\,km/hr$ and returns at a speed of $30\,km/hr$. The average speed of the car for the whole journey is............$km/hr$

If a body covers one-third of its total distance at speed $v_1$,the next one-third at speed $v_2$,and the last one-third at speed $v_3$,then the average speed will be:

Write the relation between speed and the magnitude of velocity.

Is the statement "$A$ particle can have zero speed but non-zero velocity" true or false? Explain.

$A$ motorcyclist travels a certain distance with a uniform speed of $30\, m/s$ and immediately turns back and returns to the starting point with a uniform speed of $20\, m/s$. Then the average speed of the motorcycle is ..........$m/s$ :-

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: