Speaker 1: Welcome to brain Stuff from house stuffworks dot com where
Speaker 1: smart happens. Hi Am Marshall Brain with today's question, is
Speaker 1: it more efficient to mow your yard in a spiral
Speaker 1: pattern or in an up and back pattern. One thing
Speaker 1: that complicates the answer to this question is the variables
Speaker 1: you have. The speed of the mower, the width of
Speaker 1: the mower, the dimensions of the yard, the amount of
Speaker 1: time it takes to turn, and so on. There's also
Speaker 1: the issue of things like trees and shrubs in the
Speaker 1: middle of the yard, which might make one or the
Speaker 1: other pattern better. Let's ignore trees and shrubs. Assume the
Speaker 1: mower is two feet wide and assume a square shapeyard
Speaker 1: that's a hundred feet on a side, making it a
Speaker 1: quarter acre or so. Here are the details of the paths. First,
Speaker 1: you could walk a hundred feet up one edge of
Speaker 1: the yard, make a hundred eighty degree turn, walk back
Speaker 1: another nerd feet, make a hundred eighty degree turn, and
Speaker 1: so on, and do that fifty times. Or the second
Speaker 1: option is you could walk a hundred feet up one edge,
Speaker 1: turn ninety degrees, walk feet along the edge, turn ninety degrees,
Speaker 1: and so on, spiraling in towards the center, you'd have
Speaker 1: to make spirals, with each spiral getting progressively smaller. If
Speaker 1: you go ahead and calculate the distance you have to
Speaker 1: travel for each of these two paths, it's the same.
Speaker 1: You have to walk about five thousand feet or nearly
Speaker 1: a mile. The big difference comes in the turns. In
Speaker 1: the first option you have to make forty nine hundred
Speaker 1: and eighty degree turns. In the second option you have
Speaker 1: to make nine nine degree turns. If you assume that
Speaker 1: it takes twice as long to turn a hundred eighty
Speaker 1: degrees as it does to turn ninety degrees, then the
Speaker 1: two paths are again approximately equal. If one type of
Speaker 1: turn is significantly more involved than another, or then that
Speaker 1: could shift the equation. For example, on a riding linemower,
Speaker 1: a nine degree turn is probably much easier than a
Speaker 1: hundred eighty degree turn with a walk behind. More, a
Speaker 1: hundred eighty degree turn and a ninety degree turn may
Speaker 1: differ only slightly. So the key if you want to
Speaker 1: figure this out for your own yard is to get
Speaker 1: out there with a stop watch and see which type
Speaker 1: of turn is more efficient for you. Or you could
Speaker 1: get a goat, or you could buy one of those
Speaker 1: robot line mowers to do the work for you. For
Speaker 1: more on this and thousands of other topics, is it
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