ShmoopTube

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Here's an unshmoopy question you'll find on an exam somewhere in life...

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Seventy-two kilometers per hour (km/h) is how many meters per second (m/s)?

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Here are the potential answers...

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This question is asking us to convert --

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and to get the units right.

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We have 72 KILOMETERS per HOUR which we want

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to convert to METERS per SECOND.

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Let's start by getting half way there and make it meters per hour.

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Okay, so "KILO" means a thousand.

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So 72 kilometers per hour is 72 thousand meters per hour.

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Now to get hours converted into seconds.

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Well, an hour has 60 minutes, which has 60 seconds...

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so 60 times 60 gets you 3,600 seconds in an hour.

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Go ahead and count 'em if you want to double-check. It's your hour.

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The new equation then should be 72,000 over 3,600, and that's meters per second.

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All we have to do now is reduce the number and we're there.

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Cross out the 2 zeros here and here... and we have 720 over 36.

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36 goes into 72 twice... and we have 20...

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and our answer is B -- 20 meters per second.

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