Tuesday, December 1, 2009
John Henry And The Budget Truck
I drove the rented Budget truck across Macomb to my Aunt Martha’s house. She had the desk my grandfather had made from cherry wood harvested at the farm, and which my Aunt Elizabeth had left me in her will. Brother, Tim, his 19-year old son, Conor, brother-in-law, Ed, and his son-in-law, Darren, were there to lend muscle.
We pulled the single drawer from the desk, and Ed and Darren carried the desk down the narrow stairs, through the living room, and out the front to the curb. I moved furniture to clear the path. The desk isn’t heavy, twenty pounds tops, but it is top heavy, and a little awkward to carry. The truck was around the corner, maybe two hundred feet away, and I said I’d move the truck so Ed and Darren wouldn’t have to lug the desk any further. Because the street in front of Marts’s house is a one way that would force me away from my helpers and the desk, I drove around the block. While driving I realized that the truck was using more energy than Ed and Darren would have.
Later I did the math. The amount of energy used to drive about a quarter mile is slight enough that it fades into the noise of a 440-mile trip, but it’s real. I’ve made a lot of assumptions and rounded everything, but when I guessed, I guessed in a way that would be likelier to say that Ed and Darren would have used more energy than the truck.
Truck MPG: 440 Miles/31 Gallons~14MPG (The bulk of my driving was rural, mainly Interstate, so MPG for my trip around the block was higher than 14.)
Fuel Used: 14 MPG/0.25 Mile=1/56 Gallon;
1 Gallon Gasoline=125,000 BTU;
BTU for Trip=1/56X125,000=2,232 BTU;
3.964 BTU/1 Food Calorie;
2,232/3.964=563 Food Calories Used by Truck in Going around the Block.
I used the prohealth.com exercise and activity calculator to figure how many calories Ed and Darren would have burned by carrying the desk around the corner. The calculator had them carrying bricks, but it didn’t specify how many. I assumed it would have taken them two minutes.
Calories Used by Two 150-Pound Men Carrying Bricks for Two Minutes: 36;
Factor by Which Truck Energy Use Exceeded Human Expenditure: 563/36=16.
It is a very nice desk, historically significant, and one of a kind. I needed to go to Macomb anyway.