3 ms·
Gas has an incredible amount of energy density. You can do a fun calculation as follows: If you believe this calculator, it takes 2419kJ to go 20km while cycli
by wickedchicken 15y ago
Gas has an incredible amount of energy density. You can do a fun calculation as follows:
If you believe this calculator, it takes 2419kJ to go 20km while cycling. (http://www.tribology-abc.com/calculators/cycling.htm http://www.tribology-abc.com/calculators/cycling.htm)
A gallon of gas contains about 114,000BTU (http://en.wikipedia.org/wiki/Gasoline_gallon_equivalent http://en.wikipedia.org/wiki/Gasoline_gallon_equivalent). Note that the Exxon diagram is 'per fillup' not per gallon.
So... http://www.wolframalpha.com/input/?i=%281%2F%28%282419kJ%2F20km%29%2F%28114000BTU+in+kJ%29%29%29 http://www.wolframalpha.com/input/?i=%281%2F%28%282419kJ%2F2... yields 617MPG while biking.
It's approximate, but good to know that biking is roughly an order of magnitude more efficient than cars.
- cperciva 15y agoConsidering that bicycle + cyclist is roughly an order of magnitude less massive than a car, that sounds about right. Of course, cars are also vastly more efficient at converting fuel into work than humans are.
- iliis 15y agoYes, bicycles are quite efficient. Not only compared to cars, but interestingly also to animals. While a normal human is quite bad at converting food into motion, the system bicycle+human is comparable to some of the most efficient animals. Now, if they had bicycles as well... [Source: Dad, hobby-bicyclist/mechanic]