What is the nature of the displacement$-$time graph of a body moving with constant acceleration ?

The graph given below is the distance$-$time graph of an object.

$(i)$ Find the speed of the object during first four seconds of its journey.

$(ii)$ How long was it stationary ?

$(iii)$ Does it represent a real life situation ? Justify your answer.

$(a)$ When will you say a body is in

$(i)$ uniform motion $(ii)$ non$-$uniform motion ?

$(b)$ Show the path of an object when it is in uniform motion with the help of a graph.

What can you say about the motion of a body if its displacement$-$time graph is a straight line parallel to the time axis ?

Write true or false for the following statements

Velocity and speed are measured in different units.