Question

Study the speed-time graph of a car given alongside and answer the following questions :

Figure

(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 car from O to A?
(v) What is the acceleration of car from A to B?
(vi) What is the retardation of car from B to C?

Answer 1

(i) OA represents uniform acceleration.
(ii) AB represents constant speed.
(iii) BC represents uniform retardation.
(iv)Acceleration of car from O to A = slope of line OA
$$\begin{gathered} a=\frac{\left(40-0\right)}{\left(10-0\right)}\mathrm{m}/{\mathrm{s}}^2 \\ =\boxed{4\mathrm{m}/{\mathrm{s}}^2} \end{gathered}$$
(v) Acceleration of car from A to B is zero as it has uniform speed.
(vi)Retardation of car from B to C = slope of line BC
$$\begin{gathered} a=\frac{\left(40-0\right)}{\left(50-30\right)}\mathrm{m}/{\mathrm{s}}^2 \\ =\boxed{2\mathrm{m}/{\mathrm{s}}^2} \end{gathered}$$