Area under a speed-time graph is equal to the

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 the speed-time graph for both the trains on the same paper. Also,calculate the distance travelled by each train after the brakes were applied.

What do you understand by the displacement-time graph? Draw a displacement-time graph for a girl going to school with uniform velocity. How can we calculate the uniform velocity from it?

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 $AB$?
(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 the car from $B$ to $C$?

If the acceleration of the particle is constant in magnitude but not in direction,what type of path does the particle follow?

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