If the average adult woman consumes approximately 2,000 kcal per day, how long would she need to run in order to utilize 25 percent of her caloric intake, given that the energy requirement for running is 42,000 J per minute?

Given:

Calorie intake per day = 2,000 kcal

Energy requirement for running = 42,000 J/minute

Note:

1 kcal = 4184 J

Therefore the daily caloric intake is

(2000 kcal) * (4184 J/kcal) = 8.368 x 10⁶ J

25 % of the daily caloric intake is

0.25 * (8.368 x 10⁶ J/day) = 2.092 x 10⁶ J

To utilize these calories at a consumption rate of 42,000 J per minute requires

(2.092 x 10⁶ J) / (42,000 J/min) = 49.8 minutes.

Answer: 49.8 minutes (50 minutes approximately)