Fig 8.11 shows the distance-time graph of three objects A,B and C. Study the graph and answer the following questions:
(a) Which of the three is travelling the fastest?
(b) Are all three ever at the same point on the road?
(c) How far has C travelled when B passes A?
(d) How far has B travelled by the time it passes C?
Answer
(a) Speed = Distance/Time
From the graph, we see that
A travels from 6 to 12 km in 2 hours
B travels from 0 to 12 km in 1.4 hours
C travels from 2 to 12 km in 1.6 hours
Since B travels the most distance in the smallest time,
It is travelling the fastest.
(b) All the three objects A,B and C never meet at a single point.
Thus, all the three were never at the same point on the road.
When B passes A, we have marked it by the blue dot.
Making a straight line from that point.
Where the straight line intersects line marked by A is the distance travelled.
Thus, distance travelled by A is 8 km
When B passes C, we have marked it by the blue dot.
At that point, Distance travelled by B is around 5 km .
