Draw the $v-t$ graph for constant velocity and explain it.

(N/A) Suppose an object is moving with a constant velocity $u$. Its velocity-time graph is a straight line parallel to the time axis,as shown in the figure.
The area under the $v-t$ curve between $t=0$ and $t=T$ represents the area of a rectangle with height $u$ and base $T$.
Therefore,the area is given by $\text{Area} = u \times T = uT$,which represents the displacement of the object in this time interval.
The area enclosed above the $t$-axis is considered positive,while the area enclosed below the $t$-axis is considered negative.
It is important to note that while theoretical $x-t$,$v-t$,and $a-t$ graphs may show sharp kinks,in any realistic physical situation,these functions are differentiable at all points,and the graphs are smooth. This implies that acceleration and velocity cannot change values abruptly at an instant; changes are always continuous.