{"id":60,"date":"2018-08-09T12:53:02","date_gmt":"2018-08-09T12:53:02","guid":{"rendered":"http:\/\/commons.princeton.edu\/56-terrier\/?p=60"},"modified":"2018-08-15T13:39:26","modified_gmt":"2018-08-15T13:39:26","slug":"class-7","status":"publish","type":"post","link":"http:\/\/commons.princeton.edu\/56-terrier\/2018\/08\/09\/class-7\/","title":{"rendered":"Class 7"},"content":{"rendered":"<p><strong>Reading Assignment<br \/>\n<\/strong><\/p>\n<ul>\n<li>Shop Class as Soulcraft: Chapter 4<\/li>\n<\/ul>\n<h4>In-Class Discussion<\/h4>\n<p>Zen and the Art of Motorcycle Maintenance<\/p>\n<p><strong>Chapter 10:<\/strong><\/p>\n<ul>\n<li>Theme: Scientific method &#8211; Discussion of Phaedrus&#8217; qualms with the scientific method: From one hypotheses, many emerge; it is virtually impossible to test them all. The more we test, the more we move towards chaos, rather than away from it.<\/li>\n<li>Theme: Scientific method (cont.) &#8211; The purpose of scientific method is to select a single truth from among hypothetical truths.<\/li>\n<\/ul>\n<p><strong>Chapter 11:<\/strong><\/p>\n<ul>\n<li>Theme: Classical vs. romantic; West vs. Orient; theoretic vs. esthetic<\/li>\n<li>Metaphor: Ascending into high country ~ &#8220;Climbing&#8221; arguments. Realization that philosophy tops the hierarchy of knowledge.<\/li>\n<li>Theme: Philosophy &#8211; Kant, Hume: Hume argues that sensory information is what matters, and Kant floats\u00a0<em>a priori\u00a0<\/em>notion of viewing the world, where we have preconceived ideas of what things are.<\/li>\n<li>Mechanics: Engine backfire &#8211; May result from lack of oxygen when mixture runs too lean. Exhaust pipes get hot and engine overheats. Can adjust idle &#8211; two parts &#8211; adjust mixture and then speed.<\/li>\n<\/ul>\n<p><strong>Calculations<\/strong><\/p>\n<p><strong>Finding the engine torque:<\/strong><\/p>\n<p><strong>Rear wheel &#8211; coulomb friction\/slipping force:<\/strong><\/p>\n<ul>\n<li>We calculated the torque necessary to slip the rear wheels. (We used the friction coefficient of rubber on asphalt (~1) and assumed a total burden of 400 lbs on the wheels.)<\/li>\n<li>We know F = \u03bc*n , that the frictional force is equal to the friction coefficient multiplied by the normal force (200 lbs on the rear wheel), so the force needed is 200 ft. Since\u00a0 W = F*d\u00a0 (work = force*distance), and the radius of the back wheel is 1 ft, the torque at the rear wheel is 200 ft*lbs.<\/li>\n<\/ul>\n<p><strong>Engine torque:<\/strong><\/p>\n<ul>\n<li>The engine torque multiplied by the gear ratio is this rear wheel torque, 200 ft*lbs (Energy is conserved in mechanical systems.)\u00a0The gear ratio, which is reflected in the ratio of rates at which the flywheel and rear wheel sprocket turn (6000 RPM: 840 RPM), comes out to be ~7.13. The engine torque comes out to be 200 ft*lbs\/7.13 = 28 ft*lbs.<\/li>\n<\/ul>\n<p><strong>High gear vs. low gear:<\/strong><\/p>\n<ul>\n<li>The mechanical advantage is best in low gear. \u00a0Using the\u00a0<em>Triumph<\/em>\u00a0manual, we found that the gear ratio in low gear was 21.14 as opposed to that in top gear, which was 7.13. This means that in low gear, about one-third (~21.14\/7.13) of the motor torque is required to provide the energy necessary to slip the wheels.<\/li>\n<\/ul>\n<p><strong>Lab<\/strong><\/p>\n<ul>\n<li>Frames: Wet-sanded gas tank. (Advantage of wet-sanding: keeps particles off paper; prevents paper from getting clogged)<\/li>\n<li>Bottom end: Cleaned engine case. Tested oil pump using mock distributor to spin gear and start pump. Checked springs (4) and balls (2) comprising check valves.<\/li>\n<li>Electrical: Analyzed measurements of gap in spark advance.<\/li>\n<li>Top: Parts cleaning.<\/li>\n<\/ul>\n<p>S.Y.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Reading Assignment Shop Class as Soulcraft: Chapter 4 In-Class Discussion Zen and the Art of Motorcycle Maintenance Chapter 10: Theme: Scientific method &#8211; Discussion of Phaedrus&#8217; qualms with the scientific method: From one hypotheses, many emerge; it is virtually impossible to test them all. The more we test, the more we move towards chaos, rather &hellip; <a href=\"http:\/\/commons.princeton.edu\/56-terrier\/2018\/08\/09\/class-7\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Class 7&#8221;<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-60","post","type-post","status-publish","format-standard","hentry","category-diary"],"_links":{"self":[{"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/posts\/60","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/comments?post=60"}],"version-history":[{"count":2,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/posts\/60\/revisions"}],"predecessor-version":[{"id":62,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/posts\/60\/revisions\/62"}],"wp:attachment":[{"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/media?parent=60"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/categories?post=60"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/commons.princeton.edu\/56-terrier\/wp-json\/wp\/v2\/tags?post=60"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}