Look at this distance-time graph and answer the following questions.

A distance-time graph. The line starts at 0. and after 4 seconds reaches 30 meters. From 4 to 8 seconds the line remains at 30 meters. From 8 to 10 seconds the line rises from 30 meters to 40 meters.
Question

How far did the vehicle travel in the first 4 seconds?

30 m

Question

What was the speed of the vehicle over the first 4 seconds?

distance moved = (30 m – 0 m) = 30 m

time taken = (4 s – 0 s) = 4 s

speed = gradient of distance-time graph = distance moved ÷ time taken

speed = 30 m ÷ 4 s = 7.5 m/s

Question

How long was the vehicle stationary?

The distance moved remains at 30 m between 4 and 8 seconds. The vehicle was stationary for a total of 4 seconds.

Question

What was the average speed of the vehicle over the journey?

distance moved = (40 m – 0 m) = 40 m

time taken = (10 s – 0 s) = 10 s

average speed = total distance moved ÷ time taken = 40 m ÷ 10 s = 4 m/s