Suppose a runner completes a 10K (10.0 km) road race in 42 minutes and 15 seconds. What is the runner's average speed in miles per hour?
6.21 miles in (42/60 + 15/3600)hours
0.7
To find the runner's average speed in miles per hour, we need to convert the distance from kilometers to miles and the time from minutes to hours.
Step 1: Convert the distance from kilometers to miles.
1 kilometer is approximately equal to 0.621371 miles.
So, 10.0 kilometers is equal to 10.0 * 0.621371 = 6.21371 miles.
Step 2: Convert the time from minutes to hours.
There are 60 minutes in 1 hour.
So, the time in hours is 42 minutes + (15 seconds / 60 seconds per minute) = 42 + (15 / 60) = 42.25 minutes.
Therefore, the time in hours is 42.25 / 60 = 0.704167 hours.
Step 3: Calculate the average speed.
Average speed is calculated by dividing the distance by the time.
Average speed = 6.21371 miles / 0.704167 hours = 8.826749 miles per hour.
Therefore, the runner's average speed in miles per hour is approximately 8.83 mph.
To find the runner's average speed in miles per hour, we need to convert the distance and time from metric units to imperial units.
Step 1: Convert the distance from kilometers to miles.
1 kilometer is approximately 0.621371 miles.
So, to convert 10.0 km to miles, we multiply it by 0.621371:
10.0 km * 0.621371 = 6.21371 miles.
Step 2: Convert the time from minutes and seconds to hours.
We'll first convert the 42 minutes to hours. Since there are 60 minutes in an hour:
42 minutes / 60 = 0.7 hours
Then we'll convert the 15 seconds to hours. Since there are 3600 seconds in an hour:
15 seconds / 3600 = 0.0042 hours
Step 3: Add the hours, minutes, and seconds together to get the total time in hours.
0.7 hours + 0.0042 hours = 0.7042 hours
Step 4: Calculate the average speed by dividing the distance by the time.
Average Speed = Distance / Time
Average Speed = 6.21371 miles / 0.7042 hours
Now, we can calculate the runner's average speed in miles per hour:
Average Speed = 6.21371 / 0.7042 = 8.823 miles per hour.
So, the runner's average speed is approximately 8.823 miles per hour.