Define acceleration. State a relationship connecting $u, v, a$ and $t$ for an accelerated motion. Give an example of a motion in which acceleration is uniform.

Can the speed of a body be negative ?

The $v-t$ graph of cars $A$ and $B$ which start from the same place and move along 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 ?

Four cars $A$, $B$, $C$ and $D$ are moving on a levelled road. Their distance versus time graphs are shown in Fig. Choose the correct statement

Write true or false for the following statements

In one$-$dimensional motion, the average velocity and the instantaneous velocity are unequal.