Question

Figure 1 shows the distance-time graph for two racing cars A and B. Which one of them won the race?

Answer 1

Speed is given by the expression,

$\mathrm{Speed}=\frac{\mathrm{Distance}}{\mathrm{Time}}$
It is clear from the above expression that the speed of a car is greater if it covers maximum distance in a given interval of time. To compare the distance, draw a line perpendicular to the time axis, as shown in the following distance–time graph.


From the graph, it is clear that for a given time t, the distance covered by car A is more than car B (i.e. car A is moving faster than car B). Therefore, car A won the race.