Diagram shows a velocity$-$time graph for a car starting from rest. The graph has three sections $A B$, $B C$ and $C D$
$(i)$ From a study of this graph, state how the distance travelled in any section is determined.
$(ii)$ Compare the distance travelled in section $BC$ with distance travelled in section $A B$.
$(iii)$ In which section car has zero acceleration ?
$(iv)$ Is the magnitude of acceleration higher or lower than, that of retardation ? Give reason.
$(i)$ The distance travelled under any section is calculated by finding the area of that section.
$(ii)$ Required ratio $=2: 1$
$(iii)$ In section $BC$, car has zero acceleration.
$(iv)$ Magnitude of acceleration is lower than retardation.
The magnitude of acceleration $=$ Slope of $AB =\frac{ V _{0}}{t}$
The magnitude of retardation $=$ Slope of $CD =\frac{2 V _{0}}{t}$
$(a)$ Differentiate acceleration from velocity.
$(b)$ Can a body have acceleration without change in magnitude of velocity ? Explain with an example.
$(c)$ A motor boat starting from rest on a lake accelerates in a straight line at a constant rate of $3\, m s ^{-2}$ for $8 \,s$. How far does the boat travel during this time ?
If the displacement of a body is proportional to the square of the time elapsed, what type of motion does the body possess ?
The displacement of a body is proportional to the cube of the time lapsed. The magnitude of the acceleration is
What does the odometer of an automobile measures ? Which of the following is moving faster ? Justify your answer.
$(i)$ A scooter moving with a speed of $300\, m$ per minute.
$(ii)$ A car moving with a speed of $36 \,km$ per hour.
Ali while driving to school computes the average speed for his trip to be $20\, km h^{-1}$. On his return trip along the same route there is less traffic and the average speed is $30\, km h^{-1} .$ What is the average speed for Ali's trip ?