Question

He graph below shows the velocity f(t) of a runner during a certain time interval:

Answer 1

The following that describes the intercepts on the graph is "The initial velocity of the runner was 4 m/s, and the runner stopped after 8 seconds." It is because the starting point of the line is at 4 and then the ending point is at 8.

Answer 2

Answer is "the initial velocity of the runner was 4 m/s, and the runner stopped after 8 seconds".

This is a velocity - time graph. 

At t = 0 s, the graph has a velocity as 4 m/s. This means, the runner has an initial velocity as 4 m/s. 

At t = 4 s, the runner has reached his maximum velocity as 8 m/s and acceleration is 1 m/s².

After t = 4 s, the velocity has decreased with the time means it is a negative acceleration. 

At t = 8 s, the velocity of the runner has reached to zero means runner has stopped after 8 seconds.