{"id":44,"date":"2014-04-04T02:09:24","date_gmt":"2014-04-04T02:09:24","guid":{"rendered":"http:\/\/weldnotes.com\/?p=44"},"modified":"2017-01-25T01:52:48","modified_gmt":"2017-01-25T01:52:48","slug":"what-is-pi","status":"publish","type":"post","link":"http:\/\/weldnotes.com\/?p=44","title":{"rendered":"What is Pi?"},"content":{"rendered":"<div class=\"video-container\"><iframe loading=\"lazy\" title=\"What is Pi? by WeldNotes.com\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/dAAbzBV4QQ8?feature=oembed&#038;wmode=opaque\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n<p>Engineers use pi all the time for their calculations, but what the heck is pi anyway?\u00a0 Bob and Sparky break it down for us in this video.<\/p>\n<p>Here is the video transcript:<\/p>\n<p>Let&#8217;s talk about Pi.<\/p>\n<p>Pi is one of those things in math that comes up again and again.\u00a0 It is used in formulas for the circumference of a circle, the area of a circle, volume of a sphere. I use it to calculate the cutting speed on my lathe. But what is it really?<\/p>\n<p>Well I hope this won&#8217;t be too disappointing but it really is a simple thing.\u00a0 It is the ratio of the circumference to the diameter of a circle.\u00a0 That&#8217;s it.\u00a0 Here is one way we can see what that ratio is.<\/p>\n<p>First. Let&#8217;s measure a circle&#8217;s circumference.\u00a0 Remember that the circumference is distance around the circle.\u00a0 Sparky will use a tape measure to measure the distance around this pipe.<\/p>\n<p>Ok.\u00a0 The pipe measures just a little less than 22 inches around. Now, sparky&#8217;s tape measure only measures to the nearest 16th of an inch, so let&#8217;s keep that in mind.\u00a0 Now let&#8217;s compare that to the diameter of the pipe. Sparky will now measure the diameter of the pipe.<\/p>\n<p>The diameter of this pipe is right at 7.0 inches.<\/p>\n<p>We can set these measurements up as a fraction with the circumference on top.\u00a0 This shows that the circumference is bigger than the diameter.\u00a0 How much bigger?\u00a0 Well, just do the division that the fraction is telling us&#8230;. see&#8230; 22 divided by 7 = 3.14. You see that we can write the division problem different ways, but they all mean the same thing. 22 over 7 is a division problem, we could also write it like this&#8230;. or like this&#8230;.. or like this&#8230;\u00a0 we just have to key it into the calculator with the top first, then division key, then the bottom.<\/p>\n<p>So the circumference is a little more than three times bigger than the diameter.\u00a0 This is true of any circle.\u00a0 The Circumference is a little more than 3.14 times bigger than the diameter.<\/p>\n<p>3.14 &#8212; does that sound familiar?\u00a0 If you hit the pi button on your calculator you will get number that is very close to 3.14.\u00a0 Here, I will do it on mine&#8230;&#8230;see: 3.14 15 92 65.\u00a0 This number is very close to the actual value of pi, but even it is not exact.\u00a0 Nobody knows the exact value because when you calculate it, the decimal places go on just about forever.<\/p>\n<p>Try this sometime. Measure the circumference and diameter of a piece of pipe, or a wheel (or anything round) and divide those measurements the same way (circumference on top, diameter on bottom).\u00a0 Your result will always be some approximation of pi.\u00a0 If you could measure EXACTLY, your number would be EXACTLY PI. But you can&#8217;t. That&#8217;s another story for another day.<\/p>\n<p>I hope this helps. Im bob welds and these are weldnotes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Engineers use pi all the time for their calculations, but what the heck is pi anyway?\u00a0 Bob and Sparky break it down for us in this video. Here is the video transcript: Let&#8217;s talk&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":76,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,4,3],"tags":[9,8,7,10],"class_list":["post-44","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-geometry","category-math","category-trigonometry","tag-dviison","tag-math","tag-pi","tag-ratios"],"_links":{"self":[{"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/posts\/44","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/weldnotes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=44"}],"version-history":[{"count":2,"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/posts\/44\/revisions"}],"predecessor-version":[{"id":75,"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/posts\/44\/revisions\/75"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/weldnotes.com\/index.php?rest_route=\/wp\/v2\/media\/76"}],"wp:attachment":[{"href":"http:\/\/weldnotes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=44"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/weldnotes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=44"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/weldnotes.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=44"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}