The record for a marathon is 4 h, 36 min, 21 s. The marathon distance is 90.25 km. Determine the average speed in m/s of a runner achieving this record.
t = 4h,36min,21s. = 4h,36.35min=4.61h.
r = d/t = 90.25km / 4.61h = 148.97 km/h.
To determine the average speed in m/s of a runner achieving this record, we'll need to convert the marathon distance from kilometers to meters, and then calculate the average speed.
1. Convert the marathon distance from kilometers to meters:
- There are 1000 meters in 1 kilometer.
- Multiply the marathon distance by 1000 to convert it to meters.
- 90.25 km * 1000 = 90250 meters
2. Calculate the total time taken in seconds:
- Convert the hours, minutes, and seconds into seconds.
- 4 hours = 4 * 60 * 60 = 14400 seconds
- 36 minutes = 36 * 60 = 2160 seconds
- Adding these together, we have a total of 14400 + 2160 + 21 = 16681 seconds
3. Calculate the average speed in m/s:
- Divide the distance (in meters) by the time (in seconds).
- Average speed = Distance / Time
- 90250 meters / 16681 seconds ≈ 5.41 m/s
Therefore, the average speed of a runner achieving this record is approximately 5.41 m/s.