Question

Given the speeds of each runner below, determine who runs the fastest.

\text{Stephanie runs 13 feet per second.}
Stephanie runs 13 feet per second.
\text{Emily runs 538 feet in 45 seconds.}
Emily runs 538 feet in 45 seconds.
\text{Brooke runs 1 mile in 560 seconds.}
Brooke runs 1 mile in 560 seconds.
\text{Katie runs 749 feet in 1 minute.}
Katie runs 749 feet in 1 minute.

Answer 1

Stephanie

Explanation:

To compare each runner's speed, we must convert them all to the same units.

Let's convert then all to feet per second.

1. Stephanie

Speed = 13 ft/s

2. Emily

`\text{Speed} = \frac{\text{538 ft}}{\text{45 s}} = \text{12.0 ft/s}`

3. Brooke

`\text{Speed} = \frac{\text{1 mi}}{\text{560 s}} * \frac{\text{5280 ft}}{\text{1 mi}} = \text{9.4 ft/s}`

4. Katie

`\text{ speed} = \frac{\text{747 ft}}{\text{1 min}} * \frac{\text{1 min}}{\text{60 s}} = \textbf{12.4 ft/s}`

Stephanie is the fastest runner.