$A$ particle moves along a straight line along the $x$-axis. Its position $(x)$ versus time $(t)$ graph is shown in the figure [$x$ in meters and $t$ in seconds]. Its average speed during this motion is (in $\text{ m/s}$)

$A$ particle moves for $20 \,s$ with velocity $3 \,m/s$,then with velocity $4 \,m/s$ for another $20 \,s$,and finally with velocity $5 \,m/s$ for the next $20 \,s$. What is the average velocity of the particle in $m/s$?

$A$ 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

The position $(x)$-time $(t)$ graph for a particle moving along a straight line is shown in the figure. The average speed of the particle in the time interval $t=0$ to $t=8 \, s$ is .......... $m/s$.

$A$ person goes from point $P$ to point $Q$ covering $1/3$ of the distance with speed $10 \, km/h$,the next $1/3$ of the distance at $20 \, km/h$,and the last $1/3$ of the distance at $60 \, km/h$. The average speed of the person is ............ $km/h$.

If the average velocity of a particle moving on a straight line is zero in a time interval,then: