Consider these four line graphs representing speed in meters/second, where each x-axis is labelled in seconds and each y-axis is labelled in meters. what do the four graphs have in common? a) they all indicate a constant speed. b) they all indicate an increase in speed. c) all four graphs have nothing in common. d) they all represent the same speed in m/s

Answer : (A) They all indicate a constant speed.  

Explanation :

In this case, four line graphs represent speed in m/s. The x-axis is labeled in seconds (time) and the y-axis is labeled in meters (distance).

The slope of the distance-time graph gives the slope. It can be seen from the attached figure that, in each case, the speed is constant everywhere.  

Hence, the correct option is (A) " They all indicate a constant speed ".