Answer
$16.9\text{ m/s}$
Work Step by Step
To find Secretariat's average speed in meters per second, we need to know the distance he covered and the time it took him to cover that distance.
We know that Secretariat's record run was $1.25$ miles, so we can convert that to meters by multiplying by $1609.34$:
$$1.25 \text{miles} \cdot 1609.34 \text{m/mile} = 2012.92\text{ m}.$$
We also know that the time it took Secretariat to run this distance was $1$ minute $59.2$ seconds. We convert this time to seconds:
$$1\text{ min } 59.2\text{ s} = 60\text{ s}+59.2\text{ s}=119.2\text{ s}.$$ We can now use the formula for speed:
$$\begin{aligned}
\text{speed}& = \frac{\text{distance}}{\text{time}}\\
&=\dfrac{2012.92\text{ m}}{119.2\text{ s}}\\
&\approx 16.9\text{ m/s}.
\end{aligned}$$ So, Secretariat's average speed during his record run was $16.9\text{ m/s}$.
