Respuesta :
Answer:
a) 349.4 mi/gal
b) 813.4 mi/gal
Explanation:
Given,
- 1 kcal = 1 nutritionist's Calorie = 4186 J
- Walking at 2.70 mi/h requires about 240 kcal/h.
- Riding at 11.0 mi/h, a cyclist uses food energy at a rate of about 420 kcal/h
- Gasoline yields about (1.30 × 10⁸) J/gal
a) Fuel economy in equivalent miles per gallon for a person walking.
A person walking burns 240 kcal/h walking at a speed of 2.70 mi/h
In 1 hour, a person burns 240 kcal walking 2.70 mi.
Converting kcal to J
1 kcal = 4186 J
240 kcal = 240 × 4186 = 1,004,640 J
This means, 1,004,640 J is burned walking 2.7 miles.
Gasoline yields (1.3 × 10⁸) J/gal
The fuel economy is then calculated.
1,004,640 J = 2.7 miles
(1.3 × 10⁸) J/gal = [(2.7 × 1.3 × 10⁸)/1,004,640] mi/gal
(1.3 × 10⁸) J/gal = 349.4 mi/gal.
b) Fuel economy in equivalent miles per gallon for a person bicycling.
A person bicycling burns 420 kcal/h cycling at a speed of 11.0 mi/h
In 1 hour, a person burns 420 kcal bicycling 11.0 mi.
Converting kcal to J
1 kcal = 4186 J
420 kcal = 420 × 4186 = 1,758,120 J
This means, 1,758,120 J is burned bicycling 11.0 miles.
Gasoline yields (1.3 × 10⁸) J/gal
The fuel economy is then calculated.
1,758,120 J = 11.0 miles
(1.3 × 10⁸) J/gal = [(11 × 1.3 × 10⁸)/1,758,120] mi/gal
(1.3 × 10⁸) J/gal = 813.4 mi/gal.
Hope this Helps!!!
