A boy walks to his school at a distance of $6\, km$ with constant speed of $2.5\, km/hour $ and walks back with a constant speed of $4 \,km/hr.$ His average speed for round trip expressed in $km/hour$, is
$24/13$
$40/13$
$3$
$1/2$
The position $(x)$-time $(t)$ graph for a particle moving along a straight line is shown in figure. The average speed of particle in time interval $t=0$ to $t=8 \,s$ is .......... $m / s$
Write relation between instantaneous and relative velocity for uniform motion.
Which among average speed and average velocity can be positive, negative or zero ?
A car starts from rest and moves with uniform acceleration $'a'$ on a straight road from time $t = 0$ to $t = T$ . After that, a constant deceleration $'a'$ brings it to rest. In this process the average speed of the car is
During the first $18\,min$ of a $60\,min$ trip, a car has an average speed of $11\,m / s$. What should be the average speed for remaining $42\,min$ so that car is having an average speed of $21\,m / s$ for the entire trip?