$(a)$ 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 ?

Write true or false for the following statements

Acceleration is defined as the rate of change of velocity.

What is meant by free fall ? Two bodies, one of mass $1\,g$ and other of mass $1\, kg$ are dropped from the same height in vacuum. Compare the two time intervals in which the two bodies will hit the ground.

Which of the following figures (Fig.) represents uniform motion of a moving object correctly ?

Study the speed-time graph of a car given below and answer the questions that follow

$(i)$ What type of motion is represented by $OA$ ?

$(ii)$ What type of motion is represented by $A B$ ?

$(iii)$ What type of motion is represented by $BC$ ?

$(iv)$ What is the acceleration of the car from $O$ to $A$ ?

$(v)$ What is the acceleration of the car from $A$ to $B$ ?

$(vi)$ What is the retardation of car from $B$ to $C$ ?

A body can have zero average velocity but not zero average speed. Justify.