$(a)$ Which type of motion is represented by the velocity$-$time graph shown below ?

$(b)$ Name the physical quantity which can be calculated by the area of rectangle $OABC$.

$(c)$ What does the straight line $AB$ represents ?

The driver of a train $A$ travelling at a speed of $54\, km h^{-1}$ applies brakes and retards the train uniformly The train stops in $5\, s$. Another train $B$ is travelling on the parallel track with a speed of $36\, km h ^{-1}$. This driver also applies the brakes and the train retards uniformly. The train $B$ stops in $10\, s$. Plot speed time graph for both the trains on the same paper. Also, calculate the distance travelled by each train after the brakes were applied.

An object is moving along a straight line with uniform acceleration. The following table gives the velocity of the object at various instants of time

Plot the graph.

From the graph.

$(i)$ Find the velocity of the object at the end of $2.5 sec$

$(ii)$ Calculate the acceleration.

$(iii)$ Calculate' the distance covered in the last $4$ sec.

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 ?

Give examples to distinguish

$(i)$ Distance and displacement.

$(ii)$ Speed and velocity.

$(iii)$ Acceleration and retardation.