Question 4 pls

Solution,
A velocity-time graph shows how the velocity of a moving body changes with time.
It can be used to find the following quantities in the manner shown below:
(i) Acceleration of the body:
Acceleration is rate of change of velocity.
$$\begin{gathered} a=\frac{dv}{dt} \\ and \\ \frac{dv}{dt}=slope of the v-t curve at any ins\tan t of time. \end{gathered}$$
So, it can be determined by finding the slope of the velocity - time graph at the given instant of time. It is the tangent to the curve at that instant.

(ii) The displacement of the body:
Velocity of a body is the rate of change of displacement.
$$\begin{gathered} velocity, v=\frac{dx}{dt} \\ thus, the displacement within a given time interval is given by: \\ x=\int dx={\int }_0^{t}vdt=Area bounded by the v-t curve, the velocity axis at t=0 and t=t and the time axis. \end{gathered}$$
(iii) Magnitude of displacement is equal to actual distance travelled only in case of straight line motion. In general case, where the motion is not a straight line motion distance travelled can't be determined directly from the v-t curve.