- #1
Mustard
- 21
- 1
- Homework Statement
- For saving energy, bicycling and walking are far more efficient means of transportation than is travel by automobile. For example, when riding at 10.0 mi/h, a cyclist uses food energy at a rate of about 400 kcal/h above what he would use if merely sitting still. (In exercise physiology, power is often measured in kcal/h rather than in watts. Here 1 kcal = 1 nutritionist’s Calorie = 4,186 J.) Walking at 3.00 mi/h requires about 220 kcal/h. It is interesting to compare these values with the energy consumption required for travel by car. Gasoline yields about 1.30 x 10^8 J/gal. Find the fuel economy in equivalent miles per gallon for a person (a) walking and (b) bicycling
- Relevant Equations
- 3.00 mi/h = 220 kcal/h
10.0 mi/h = 400 kcal/h above the values of sitting still
1 kcal = 1 nutritionist’s Calorie = 4,186 J
Gasoline yield = 1.30 x 10^8 J/gal
So I'm guessing we need our end unit to be in MPG?
a) walking
( 220 kcal/ 1 hr )⋅ ( 1hr / 3 mile ) = 73 .3 kcal/mi⋅⋅
(73 .3 kcal/ 1 mile) ⋅ (4,186 J/1 kcal) = 3,06833.8 J/mi
(1.30 x 10^8 J/ 1 gal)(1 mile / 3,06833.8 J) = 423.68 MPG
b) bicycling
Not sure as it says,"...when riding at 10.0 mi/h, a cyclist uses food energy at a rate of about 400 kcal/h above what he would use if merely sitting still." So I am guessing I would need to get those values for sitting still and add them to get the cyclist values?
a) walking
( 220 kcal/ 1 hr )⋅ ( 1hr / 3 mile ) = 73 .3 kcal/mi⋅⋅
(73 .3 kcal/ 1 mile) ⋅ (4,186 J/1 kcal) = 3,06833.8 J/mi
(1.30 x 10^8 J/ 1 gal)(1 mile / 3,06833.8 J) = 423.68 MPG
b) bicycling
Not sure as it says,"...when riding at 10.0 mi/h, a cyclist uses food energy at a rate of about 400 kcal/h above what he would use if merely sitting still." So I am guessing I would need to get those values for sitting still and add them to get the cyclist values?
