Answer:
0.79 Watts
Step-by-step explanation:
2 hours is 2 * 60 = 120 minutes
If you take 8 minutes per mile, you can run:
120/8 = 15 miles in 2 hours
Per mile calories consumption is 91, so in 15 miles:
91 * 15 = 1365
Average Power Output is Energy by Time
Also, calories to joules is:
1 Calorie = 4.184 Joules
So 1365 calorie is:
1365 * 4.184 = 5711.16 Joules
and 2 hours in seconds is 2 * 60 * 60 = 7200 seconds
Now
Average Power Output = 5711.16/7200 = 0.79 Watts