John-Paul Flintoff of the Times drove to Oxford and back, a total of a hundred miles, and noticed that he had a bottle of water on the seat. He wondered how much energy it took to move it.
I converted the weight of the bottle (1 kilo) into pounds, and divided the distance (100 miles) into feet, using one of many online conversion sites. Then I converted the total number of foot-pounds into kilowatt hours. The result: 0.437 477 242 4.
In other words, if I had left the bottle at home I could more usefully have used the same amount of energy to light my house all evening.
But I am not certain about his math or physics; a foot-pound is the "the amount of energy expended when a force of one pound acts through a distance of one foot along the direction of the force." and he has calculated the distance and the force, but surely it takes more energy to move the water in a Land Rover than in his Golf, even though it is the same amount of water. Any physicists out there with the answer? TimesOnline