What is the slope of the displacement $-$ time graph when the body has uniform motion?

Give an expression for the speed of an athlete if he takes time $t$ to complete one round of a circular track of radius $r$.

Explain with reason,which of the following graphs can possibly represent the motion of a particle observed in nature?

The velocity-time graph of a truck is plotted below.
$(a)$ Calculate the magnitude of displacement of the truck in $15$ seconds.
$(b)$ During which part of the journey was the truck decelerating?
$(c)$ Calculate the magnitude of average velocity of the truck.

What does the slope of the velocity$-$time graph represent?

What does the slope of a displacement$-$time graph represent? Can a displacement$-$time graph be parallel to the displacement axis? Give a reason for your answer.