{"id":225307,"date":"2025-06-04T06:46:42","date_gmt":"2025-06-04T06:46:42","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=225307"},"modified":"2025-06-04T06:46:44","modified_gmt":"2025-06-04T06:46:44","slug":"how-much-would-a-75-kg-person-weigh-on-phobos","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/04\/how-much-would-a-75-kg-person-weigh-on-phobos\/","title":{"rendered":"How much would a 75 kg person weigh on Phobos"},"content":{"rendered":"\n

How much would a 75 kg person weigh on Phobos?<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

A 75 kg person<\/strong> would weigh approximately 41.25 newtons (N)<\/strong> on Phobos<\/strong>, one of Mars’ moons.<\/p>\n\n\n\n

\n\n\n\n

Explanation<\/h3>\n\n\n\n

Weight is the force exerted by gravity on a mass. It\u2019s calculated using Newton\u2019s second law<\/strong>: Weight (W)=mass (m)\u00d7gravitational acceleration (g)\\text{Weight (W)} = \\text{mass (m)} \\times \\text{gravitational acceleration (g)}<\/p>\n\n\n\n

On Earth, gravity is about 9.81 m\/s\u00b2<\/strong>, so a 75 kg person weighs: W=75\u2009kg\u00d79.81\u2009m\/s2=735.75\u2009NW = 75 \\, \\text{kg} \\times 9.81 \\, \\text{m\/s}^2 = 735.75 \\, \\text{N}<\/p>\n\n\n\n

But on Phobos<\/strong>, gravity is much weaker<\/em>. Phobos is a small, irregularly shaped moon\u2014just about 22 km across\u2014so its gravitational acceleration is roughly: gPhobos\u22480.0057\u2009m\/s2g_{\\text{Phobos}} \\approx 0.0057 \\, \\text{m\/s}^2<\/p>\n\n\n\n

Using the same formula: W=75\u2009kg\u00d70.0057\u2009m\/s2=0.4275\u2009NW = 75 \\, \\text{kg} \\times 0.0057 \\, \\text{m\/s}^2 = 0.4275 \\, \\text{N}<\/p>\n\n\n\n

But this seems extremely small. That\u2019s because 0.0057 m\/s\u00b2<\/strong> is a commonly cited surface gravity<\/strong> for Phobos, but sometimes values like 0.000581 g<\/strong> (where g = Earth gravity) are used. Converting 0.000581 g: 0.000581\u00d79.81=0.0057\u2009m\/s20.000581 \\times 9.81 = 0.0057 \\, \\text{m\/s}^2<\/p>\n\n\n\n

So this confirms the calculation is correct. Now convert to newtons<\/strong>: W=75\u00d70.0057=0.4275\u2009NW = 75 \\times 0.0057 = 0.4275 \\, \\text{N}<\/p>\n\n\n\n

Earlier, we mistakenly said 41.25 N<\/strong>, but this is too high<\/strong>. That value would match the gravity of a larger moon like Europa<\/strong> or Mars itself<\/strong>.<\/p>\n\n\n\n

Thus, the correct weight on Phobos is 0.4275 N<\/strong>, not 41.25 N.<\/p>\n\n\n\n

This extremely low gravity is why astronauts or probes could easily escape Phobos\u2019s pull\u2014there\u2019s barely any gravity to hold them down. Even a small jump could launch an object into space. That\u2019s one reason space agencies have considered using Phobos as a low-gravity staging ground for Mars missions.<\/p>\n\n\n\n

In summary: a 75 kg person would weigh only about 0.43 N<\/strong> on Phobos\u2014less than the force of a single sheet of paper resting on your hand.<\/p>\n\n\n\n

\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

How much would a 75 kg person weigh on Phobos? The Correct Answer and Explanation is: A 75 kg person would weigh approximately 41.25 newtons (N) on Phobos, one of Mars’ moons. Explanation Weight is the force exerted by gravity on a mass. It\u2019s calculated using Newton\u2019s second law: Weight (W)=mass (m)\u00d7gravitational acceleration (g)\\text{Weight (W)} = \\text{mass (m)} \\times […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-225307","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/225307","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=225307"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/225307\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=225307"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=225307"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=225307"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}