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

$A$ cyclist driving at $5\, m s^{-1}$ picks up a velocity of $10\, m s^{-1}$ over a distance of $50\, m$. Calculate $(i)$ acceleration $(ii)$ time in which the cyclist picks up the above velocity.

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.

The $v-t$ graph of cars $A$ and $B$ which start from the same place and move along a straight road in the same direction is shown. Calculate:
$(i)$ The acceleration of car $A$ between $0$ and $8\, s$.
$(ii)$ The acceleration of car $B$ between $2\, s$ and $4\, s$.
$(iii)$ The points of time at which both the cars have the same velocity.
$(iv)$ Which of the two cars is ahead after $8\, s$ and by how much?

Why does $(second)^{2}$ occur in the unit of acceleration?

$(a)$ Define uniform circular motion.
$(b)$ Is the uniform circular motion an accelerated motion? Give reasons for your answer.