On Fri, Feb 21, 2014 at 12:06 AM, Charles Haynes <[email protected]>wrote:
> the fuel efficiency of a car is often expressed as litres of petrol per > 100km, right? litres of petrol per 100km is length^3/length = length^2. > What is the "real world" significance of this area? > It's the area of the column of fuel necessary and sufficient to keep the car moving. Imagine a car with a "fuel scoop" continuously sucking up fuel as it drove. The area above is the diameter of the column of fuel it would have to suck up in order to be just enough to keep moving. Visualise it thus. Take the number of litres in the formula and stretch it till it's a column 100km long. The vehicle will completely consume that fuel while it traverses that distance. The area is the area of the cross section of the column. -- Charles
