{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":369,"title":"Basic electricity in a dry situation","description":"\u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \r\n\r\nThis is a very hypothetical situation between two individuals in a very dry atmosphere. \r\n\r\nHe came running in rubber boots when she was combing her hair. \r\n\r\nAround N number of electrons moved from one person to the other upon contact. \r\n\r\nWhat was the voltage between them before the contact? \r\n\r\nAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads. \r\n\r\nPlease assume that every electron carries about 160 zepto coulombs.\r\n\r\nFor more info on capacitors: \u003chttps://en.wikipedia.org/wiki/Capacitor\u003e","description_html":"\u003cp\u003e\u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889\u003c/p\u003e\u003cp\u003eThis is a very hypothetical situation between two individuals in a very dry atmosphere.\u003c/p\u003e\u003cp\u003eHe came running in rubber boots when she was combing her hair.\u003c/p\u003e\u003cp\u003eAround N number of electrons moved from one person to the other upon contact.\u003c/p\u003e\u003cp\u003eWhat was the voltage between them before the contact?\u003c/p\u003e\u003cp\u003eAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads.\u003c/p\u003e\u003cp\u003ePlease assume that every electron carries about 160 zepto coulombs.\u003c/p\u003e\u003cp\u003eFor more info on capacitors: \u003ca href = \"https://en.wikipedia.org/wiki/Capacitor\"\u003ehttps://en.wikipedia.org/wiki/Capacitor\u003c/a\u003e\u003c/p\u003e","function_template":"function V = volts(N)\r\n  V = 10000;\r\nend","test_suite":"%%\r\nN = 10^10;\r\nV = 150;\r\nassert(volts(N)\u003eV/pi)\r\n%%\r\nN = 10^11;\r\nV = 700;\r\nassert(volts(N)\u003cV*pi)\r\n%%\r\nN = 10^12;\r\nV = 10000;\r\nassert(volts(N)\u003eV/sqrt(pi))\r\n","published":true,"deleted":false,"likes_count":8,"comments_count":4,"created_by":166,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":598,"test_suite_updated_at":"2012-02-20T20:05:18.000Z","rescore_all_solutions":false,"group_id":34,"created_at":"2012-02-20T20:05:18.000Z","updated_at":"2026-05-08T02:17:56.000Z","published_at":"2017-10-16T01:45:05.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis is a very hypothetical situation between two individuals in a very dry atmosphere.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHe came running in rubber boots when she was combing her hair.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAround N number of electrons moved from one person to the other upon contact.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWhat was the voltage between them before the contact?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease assume that every electron carries about 160 zepto coulombs.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor more info on capacitors:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Capacitor\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://en.wikipedia.org/wiki/Capacitor\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":369,"title":"Basic electricity in a dry situation","description":"\u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \r\n\r\nThis is a very hypothetical situation between two individuals in a very dry atmosphere. \r\n\r\nHe came running in rubber boots when she was combing her hair. \r\n\r\nAround N number of electrons moved from one person to the other upon contact. \r\n\r\nWhat was the voltage between them before the contact? \r\n\r\nAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads. \r\n\r\nPlease assume that every electron carries about 160 zepto coulombs.\r\n\r\nFor more info on capacitors: \u003chttps://en.wikipedia.org/wiki/Capacitor\u003e","description_html":"\u003cp\u003e\u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889 \u0026#9889\u003c/p\u003e\u003cp\u003eThis is a very hypothetical situation between two individuals in a very dry atmosphere.\u003c/p\u003e\u003cp\u003eHe came running in rubber boots when she was combing her hair.\u003c/p\u003e\u003cp\u003eAround N number of electrons moved from one person to the other upon contact.\u003c/p\u003e\u003cp\u003eWhat was the voltage between them before the contact?\u003c/p\u003e\u003cp\u003eAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads.\u003c/p\u003e\u003cp\u003ePlease assume that every electron carries about 160 zepto coulombs.\u003c/p\u003e\u003cp\u003eFor more info on capacitors: \u003ca href = \"https://en.wikipedia.org/wiki/Capacitor\"\u003ehttps://en.wikipedia.org/wiki/Capacitor\u003c/a\u003e\u003c/p\u003e","function_template":"function V = volts(N)\r\n  V = 10000;\r\nend","test_suite":"%%\r\nN = 10^10;\r\nV = 150;\r\nassert(volts(N)\u003eV/pi)\r\n%%\r\nN = 10^11;\r\nV = 700;\r\nassert(volts(N)\u003cV*pi)\r\n%%\r\nN = 10^12;\r\nV = 10000;\r\nassert(volts(N)\u003eV/sqrt(pi))\r\n","published":true,"deleted":false,"likes_count":8,"comments_count":4,"created_by":166,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":598,"test_suite_updated_at":"2012-02-20T20:05:18.000Z","rescore_all_solutions":false,"group_id":34,"created_at":"2012-02-20T20:05:18.000Z","updated_at":"2026-05-08T02:17:56.000Z","published_at":"2017-10-16T01:45:05.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889 \u0026amp;#9889\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis is a very hypothetical situation between two individuals in a very dry atmosphere.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHe came running in rubber boots when she was combing her hair.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAround N number of electrons moved from one person to the other upon contact.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWhat was the voltage between them before the contact?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssume it is a simple RC type electrical circuit with equivalent capacitance of about 16 pico farads.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease assume that every electron carries about 160 zepto coulombs.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor more info on capacitors:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Capacitor\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://en.wikipedia.org/wiki/Capacitor\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[{"value":"Cody5:Easy","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"static\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}