To do the math, you need to know:
1. The average snowfall per year — 70.6 inches, or nearly 6 feet, recorded in Anchorage from 1952 to 2000. (www.alaska.com)
2. The weight of a cubic foot of water — 62.418 pounds
3. The percentage of water per cubic foot of snow — We’ll use 20 percent, although it can range to 60.
4. The area of your driveway — We’ll use 20 feet wide by 40 feet long, although many driveways are much longer.
* Multiply the length of the driveway times the width to find the area: 20 x 40 = 800 square feet.
* Multiply the driveway area by the average amount of snow in feet: 800 x 6 = 4,800 cubic feet of snow
* Multiply the weight of a cubic foot of water times the percentage of water it contains: 62.418 x .20 = 12.48 pounds per cubic foot of snow.
* Multiply the weight of a cubic foot of snow by the number of cubic feet of snow: 12.48 x 4,800 = 59,904 pounds of snow.
By the same calculations, if you live in Girdwood (average snowfall 195.5 inches from 1963-2000), the total would be (16.29 x 800 x 12.48) 162,639 pounds.
Here’s why it’s important to keep that shovel load of snow close to your body, based on the principle of torque. (To envision the principle, imagine you are loosening a nut or bolt on an engine. You put a wrench on it, but it doesn’t budge. When you apply a longer handle, it moves easily. Another way is to envision how far toward the middle, or fulcrum, of a teeter totter a heavy child must sit in order to be lifted by a child who is much lighter.)
Say you have a plastic snow shovel full of snow that weighs 12 pounds held 3 feet away from your body. To figure the torque, multiply the weight times the distance, or 12 x 3 = 36 pounds.
“That’s why bending over when you pick up a shovel full is so bad,” Ennis said.
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