The record for a marathon is 1 h, 21 min, 21 s. The marathon distance is 25.84 km. Determine the average speed in m/s of a runner achieving this record.
To determine the average speed of a runner achieving this record, we need to convert the time and distance into a common unit.
First, let's convert the time from hours, minutes, and seconds into seconds. We have:
1 hour = 60 minutes = 60 * 60 = 3600 seconds
21 minutes = 21 * 60 = 1260 seconds
21 seconds = 21 seconds
Therefore, the total time in seconds is 3600 + 1260 + 21 = 4881 seconds.
Next, let's convert the distance from kilometers to meters. We know that 1 kilometer is equal to 1000 meters. So, the marathon distance of 25.84 km is equal to 25.84 * 1000 = 25840 meters.
Now that we have the time in seconds and the distance in meters, we can calculate the average speed. The formula for average speed is:
Average Speed = Distance / Time
Plugging in the values, we have:
Average Speed = 25840 meters / 4881 seconds
Dividing the distance by the time, we get:
Average Speed ≈ 5.29 m/s
Therefore, the average speed of a runner achieving this record is approximately 5.29 meters per second.