{"id":517,"date":"2015-10-12T16:00:04","date_gmt":"2015-10-12T16:00:04","guid":{"rendered":"https:\/\/maritimesa.org\/grade-10\/?p=517"},"modified":"2021-03-19T10:33:19","modified_gmt":"2021-03-19T10:33:19","slug":"difference-in-time","status":"publish","type":"post","link":"https:\/\/maritimesa.org\/grade-10\/difference-in-time\/","title":{"rendered":"Difference in Time"},"content":{"rendered":"<p>[vc_row][vc_column][vc_video link=&#8221;https:\/\/vimeo.com\/473740273&#8243;][vc_video link=&#8221;https:\/\/vimeo.com\/505311442&#8243;][vc_column_text]<a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-large wp-image-507\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-1024x719.png\" alt=\"10_1_3_Time_Zones_01\" width=\"1024\" height=\"719\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-1024x719.png 1024w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-300x211.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-208x146.png 208w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-50x35.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01-107x75.png 107w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/10_1_3_Time_Zones_01.png 1200w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Lines of longitude run from the North Pole to the South Pole. They are \u201clabeled\u201d from the Greenwich Meridian which has the value of 0<sup>\u02da<\/sup>.<\/p>\n<ul>\n<li>Lines of Longitude on the eastern side (<em>to the right<\/em>) of the Greenwich Meridian increase in value until 180<span style=\"font-size: small\">\u02da E.<\/span><\/li>\n<li>Lines of Longitude on the western side (<em>to the left<\/em>) of the Greenwich Meridian increase in value until 180\u02da\u00a0W.<\/li>\n<\/ul>\n<ul>\n<li>Strangely, the Lines of Longitude 180\u02da\u00a0E and 180\u02da\u00a0W are the same line of longitude, and this Line of Longitude is known as the International Date Line. It does not cut through any country and therefore has several parts that are not straight. This is to avoid confusion over the date within a country.<\/li>\n<\/ul>\n<ul>\n<li>For every 15 degrees difference in Longitude, <strong>sun time<\/strong> changes by one hour.<\/li>\n<\/ul>\n<p>This means, for example, that :<\/p>\n<p>PLACE A that is 15 degrees of longitude different to PLACE B will have a time difference of one hour (<strong>sun time<\/strong>).<\/p>\n<p><a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-508\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1.png\" alt=\"Sun_Time_Calculation_1\" width=\"837\" height=\"374\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1.png 837w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1-300x134.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1-260x116.png 260w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1-50x22.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_1-150x67.png 150w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/a><\/p>\n<p>PLACE C that is 45 degrees different to PLACE D will have a time difference of three hours (<strong>sun time<\/strong>)<\/p>\n<p><a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-509\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2.png\" alt=\"Sun_Time_Calculation_2\" width=\"837\" height=\"374\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2.png 837w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2-300x134.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2-260x116.png 260w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2-50x22.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_2-150x67.png 150w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/a><\/p>\n<p>PLACE X that is 150 degrees different to PLACE Y will have a time difference of ten hours (<strong>sun time<\/strong>).<\/p>\n<p><a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-510\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3.png\" alt=\"Sun_Time_Calculation_3\" width=\"837\" height=\"374\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3.png 837w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3-300x134.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3-260x116.png 260w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3-50x22.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_3-150x67.png 150w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/a><\/p>\n<p>You will notice that these places are all on the eastern side of the Greenwich Meridian and the rules are that<\/p>\n<ul>\n<li>if the two labels are the <span style=\"color: #ff0000\"><strong>S<\/strong><\/span>AME (i.e. both are labeled E or both are labeled W), you must <span style=\"color: #ff0000\"><strong>S<\/strong><\/span>UBTRACT the smaller value from the greater value.<\/li>\n<li>if the two labels are <span style=\"color: #ff0000\"><strong>D<\/strong><\/span>IFFERENT (i.e. one is labeled E and the other is labeled W), you must A<span style=\"color: #ff0000\"><strong>DD<\/strong><\/span> the two values.<\/li>\n<\/ul>\n<p><em>Note the letters in red that will help you to remember whether to subtract or add when getting your answer.<\/em><\/p>\n<p>Look at the example below where the places are both on the western side of the Greenwich Meridian, and both have the label W, i.e. they are the <span style=\"color: #ff0000\"><strong>S<\/strong><\/span>AME. To find the difference in longitude, we must <span style=\"color: #ff0000\"><strong>S<\/strong><\/span>UBTRACT the smaller value from the greater value:<\/p>\n<p><a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-511\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4.png\" alt=\"Sun_Time_Calculation_4\" width=\"837\" height=\"374\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4.png 837w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4-300x134.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4-260x116.png 260w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4-50x22.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_4-150x67.png 150w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/a><\/p>\n<p>Look at the example below where one place is on the western side of the Greenwich Meridian (and labeled W), while the other is on the eastern side of the Greenwich Meridian (and labeled E). As these labels are <span style=\"color: #ff0000\"><strong>D<\/strong><\/span>IFFERENT, we need to A<span style=\"color: #ff0000\"><strong>DD<\/strong><\/span> the two values to find the difference in longitude.<\/p>\n<p><a href=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-512\" src=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5.png\" alt=\"Sun_Time_Calculation_5\" width=\"837\" height=\"374\" srcset=\"https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5.png 837w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5-300x134.png 300w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5-260x116.png 260w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5-50x22.png 50w, https:\/\/maritimesa.org\/grade-10\/wp-content\/uploads\/sites\/2\/2015\/10\/Sun_Time_Calculation_5-150x67.png 150w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/a><\/p>\n<h4><span style=\"color: #003b67\"><strong>Test yourself : Difference in Time<\/strong><\/span><\/h4>\n<p><span style=\"color: #003b67\">What is the difference in time between the following places?<\/span><\/p>\n<p><span style=\"color: #003b67\"><strong>1.<\/strong> Place A (30\u02da\u00a0E) and Place B (90\u02da\u00a0E)<\/span><\/p>\n<p><span style=\"color: #003b67\"><strong>2.<\/strong> Place C (30\u02da\u00a0E) and Place D (150\u02da\u00a0E)<\/span><\/p>\n<p><span style=\"color: #003b67\"><strong>3.<\/strong>\u00a0Place E (30\u02da\u00a0W) and Place F (165\u02da\u00a0W)<\/span><\/p>\n<p><span style=\"color: #003b67\"><strong>4.<\/strong>\u00a0Place G (30\u02da\u00a0W) and Place H (90\u02da\u00a0E)<\/span><\/p>\n<p><span style=\"color: #003b67\"><strong>5.<\/strong>\u00a0Place I (120\u02da\u00a0E) and Place J (45\u02da\u00a0W)<\/span>[\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>[vc_row][vc_column][vc_video link=&#8221;https:\/\/vimeo.com\/473740273&#8243;][vc_video link=&#8221;https:\/\/vimeo.com\/505311442&#8243;][vc_column_text] Lines of longitude run from the North Pole to the South Pole. They are \u201clabeled\u201d from the Greenwich Meridian which has the value of 0\u02da. Lines of Longitude on the eastern side (to the right) of the Greenwich Meridian increase in value until 180\u02da E. Lines of [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[],"class_list":["post-517","post","type-post","status-publish","format-standard","hentry","category-10-1-3-time-zones"],"_links":{"self":[{"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/posts\/517"}],"collection":[{"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/comments?post=517"}],"version-history":[{"count":13,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/posts\/517\/revisions"}],"predecessor-version":[{"id":1398,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/posts\/517\/revisions\/1398"}],"wp:attachment":[{"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/media?parent=517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/categories?post=517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/maritimesa.org\/grade-10\/wp-json\/wp\/v2\/tags?post=517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}