Question

question / (1 point)
a runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. what is the average speed of the runner in m/s?
14.2 × 10^3 m/s
124 m/s
3.95 m/s
14.2 m/s

Explanation:

Step1: Convert distance to meters

The distance of the marathon is 42.0 km. Since 1 km = 1000 m, we convert kilometers to meters by multiplying by 1000.
$42.0\ km\times1000\ \frac{m}{km} = 42000\ m$

Step2: Convert time to seconds

The time is 2 hours and 57 minutes. First, convert hours to minutes: 2 hours = $2\times60 = 120$ minutes. Then total minutes = $120 + 57 = 177$ minutes. Now convert minutes to seconds: 1 minute = 60 seconds, so $177\ min\times60\ \frac{s}{min}= 10620\ s$

Step3: Calculate average speed

Average speed $v$ is given by the formula $v=\frac{d}{t}$, where $d$ is distance and $t$ is time.
Substitute $d = 42000\ m$ and $t = 10620\ s$ into the formula:
$v=\frac{42000}{10620}\approx3.95\ m/s$

Answer:

3.95 m/s (the option corresponding to this value, e.g., if the option is labeled as the third one with "3.95 m/s", then the answer is that option. Assuming the options are in the order given, the answer is the third option: 3.95 m/s)