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Speaker 1: Welcome to brain Stuff from house stuffworks dot com where

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Speaker 1: smart happens. Hi Am Marshall Brain with today's question, is

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Speaker 1: it more efficient to mow your yard in a spiral

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Speaker 1: pattern or in an up and back pattern. One thing

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Speaker 1: that complicates the answer to this question is the variables

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Speaker 1: you have. The speed of the mower, the width of

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Speaker 1: the mower, the dimensions of the yard, the amount of

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Speaker 1: time it takes to turn, and so on. There's also

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Speaker 1: the issue of things like trees and shrubs in the

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Speaker 1: middle of the yard, which might make one or the

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Speaker 1: other pattern better. Let's ignore trees and shrubs. Assume the

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Speaker 1: mower is two feet wide and assume a square shapeyard

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Speaker 1: that's a hundred feet on a side, making it a

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Speaker 1: quarter acre or so. Here are the details of the paths. First,

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Speaker 1: you could walk a hundred feet up one edge of

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Speaker 1: the yard, make a hundred eighty degree turn, walk back

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Speaker 1: another nerd feet, make a hundred eighty degree turn, and

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Speaker 1: so on, and do that fifty times. Or the second

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Speaker 1: option is you could walk a hundred feet up one edge,

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Speaker 1: turn ninety degrees, walk feet along the edge, turn ninety degrees,

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Speaker 1: and so on, spiraling in towards the center, you'd have

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Speaker 1: to make spirals, with each spiral getting progressively smaller. If

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Speaker 1: you go ahead and calculate the distance you have to

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Speaker 1: travel for each of these two paths, it's the same.

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Speaker 1: You have to walk about five thousand feet or nearly

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Speaker 1: a mile. The big difference comes in the turns. In

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Speaker 1: the first option you have to make forty nine hundred

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Speaker 1: and eighty degree turns. In the second option you have

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Speaker 1: to make nine nine degree turns. If you assume that

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Speaker 1: it takes twice as long to turn a hundred eighty

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Speaker 1: degrees as it does to turn ninety degrees, then the

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Speaker 1: two paths are again approximately equal. If one type of

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Speaker 1: turn is significantly more involved than another, or then that

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Speaker 1: could shift the equation. For example, on a riding linemower,

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Speaker 1: a nine degree turn is probably much easier than a

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Speaker 1: hundred eighty degree turn with a walk behind. More, a

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Speaker 1: hundred eighty degree turn and a ninety degree turn may

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Speaker 1: differ only slightly. So the key if you want to

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Speaker 1: figure this out for your own yard is to get

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Speaker 1: out there with a stop watch and see which type

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Speaker 1: of turn is more efficient for you. Or you could

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Speaker 1: get a goat, or you could buy one of those

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Speaker 1: robot line mowers to do the work for you. For

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Speaker 1: more on this and thousands of other topics, is it

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