In order to calculate the speed, we can use the formula below:
[tex]speed=\frac{distance}{time}[/tex]Now, using the distance traveled of 125 meters in the interval of time of 15 seconds, the speed is:
[tex]\begin{gathered} speed=\frac{125}{15}\\ \\ speed=8.33\text{ m/s} \end{gathered}[/tex]Therefore the speed is 8.33 m/s.