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.
Interval 3 (Greatest), Interval 2 (Least) Positive (Intervals $1$ and $2$), Negative (Interval 3 ) The average speed of a particle shown in the $x-t$ graph is obtained from the slope of the graph in a particular interval of time. It is clear from the graph that the slope is maximum and minimum restively in intervals 3 and 2 respectively. Therefore, the average speed of the particle is the greatest in interval 3 and is the least in interval $2 .$ The sign of average velocity is positive in both intervals 1 and 2 as the slope is positive in these intervals. However, it is negative in interval 3 because the slope is negative in this interval.
Which informations cannot be drawn from average velocity ?
A ball thrown up from a location, returns back at the same location. Which of the following statements are correct.
$(a)$ Distance travelled by ball can be zero
$(b)$ Displacement of ball is zero
$(c)$ Average velocity of ball is zero
$(d)$ Acceleration of the ball is zero
Write relation between speed and magnitude of velocity.
A body covers first one-third of the distance with a velocity $20\, ms^{-1}$, the second one-third with a velocity of $30\, ms^{-1}$ and last one-third with a velocity of $40\, ms^{-1}$. The average velocity is nearly........$m/s$
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