{"id":3419,"date":"2025-07-21T11:22:13","date_gmt":"2025-07-21T11:22:13","guid":{"rendered":"https:\/\/odeacademy.in\/?p=3419"},"modified":"2025-07-21T14:30:22","modified_gmt":"2025-07-21T14:30:22","slug":"motion-force-and-gravitation","status":"publish","type":"post","link":"https:\/\/thequickknowledge.com\/exam\/motion-force-and-gravitation\/","title":{"rendered":"Motion, Force and Gravitation &#8211; Physics | General Science"},"content":{"rendered":"<h4 style=\"text-align: center;\">Motion, Force, and Gravitation Relate to Mass &amp; Weight<\/h4>\n<hr \/>\n<p data-start=\"143\" data-end=\"560\">An object may appear to be at rest or in motion depending on the observer\u2019s frame of reference. For example, passengers inside a moving bus see each other at rest, but an observer outside sees them in motion.<\/p>\n<p data-start=\"562\" data-end=\"605\"><strong data-start=\"562\" data-end=\"581\">Types of Motion<\/strong> :<\/p>\n<ul data-start=\"606\" data-end=\"692\">\n<li><strong data-start=\"608\" data-end=\"632\">Straight-line motion<\/strong><\/li>\n<li><strong data-start=\"635\" data-end=\"654\">Circular motion<\/strong><\/li>\n<li><strong data-start=\"657\" data-end=\"692\">Rotational and vibratory motion<\/strong><\/li>\n<li><strong data-start=\"1251\" data-end=\"1269\">Uniform motion<\/strong>: Equal distances in equal time intervals.<\/li>\n<li><strong data-start=\"1314\" data-end=\"1336\">Non-uniform motion<\/strong>: Unequal distances in equal time intervals.<\/li>\n<\/ul>\n<p><strong>Key Concepts:<\/strong><\/p>\n<ul>\n<li><strong>Distance<\/strong> is the total path covered.<\/li>\n<li><strong>Displacement<\/strong> is the shortest straight-line distance from initial to final position.<\/li>\n<li><strong data-start=\"957\" data-end=\"966\">Speed<\/strong>: Distance traveled per unit time. SI unit is m\/s. Average Speed = Total distance \/ Total tim<\/li>\n<li><strong>Velocity<\/strong>: Speed with direction. Can be uniform or variable. Average Velocity = (u + v) \/ 2<\/li>\n<li><strong data-start=\"1235\" data-end=\"1251\">Acceleration<\/strong>: Rate of change of velocity. SI unit is m\/s\u00b2. a = (v-u)\/t<\/li>\n<\/ul>\n<p><strong>Equations of Motion<\/strong><\/p>\n<ul>\n<li>v = u + at<\/li>\n<li>s = ut + (1\/2)at\u00b2<\/li>\n<li>v\u00b2 = u\u00b2 + 2as<\/li>\n<\/ul>\n<p style=\"padding-left: 40px;\">Where, u: Initial velocity, v: Final velocity, a: Acceleration, t: Time, s: Displacement<\/p>\n<p data-start=\"840\" data-end=\"882\">Historically, it was believed that rest is the natural state of objects. Galileo Galilei and Isaac Newton challenged this idea and introduced a new approach using the concept of <strong data-start=\"538\" data-end=\"547\">force.<\/strong><\/p>\n<ul>\n<li data-start=\"840\" data-end=\"882\">The <strong data-start=\"188\" data-end=\"208\">SI unit of force<\/strong> is <strong data-start=\"212\" data-end=\"226\">newton (N)<\/strong>, where 1 N = 1 kg\u00b7m\/s\u00b2.<\/li>\n<\/ul>\n<p data-start=\"840\" data-end=\"882\"><strong data-start=\"844\" data-end=\"882\">Balanced and Unbalanced Forces<\/strong><\/p>\n<ul>\n<li data-start=\"884\" data-end=\"1270\"><strong data-start=\"49\" data-end=\"69\">Balanced Forces:<\/strong> Equal and opposite forces cancel out; no movement occurs.<\/li>\n<li data-start=\"884\" data-end=\"1270\"><strong data-start=\"130\" data-end=\"152\" data-is-only-node=\"\">Unbalanced Forces:<\/strong> Unequal forces cause motion in the direction of the stronger force.<\/li>\n<\/ul>\n<p data-start=\"884\" data-end=\"1270\"><strong>Law of Motion<\/strong><\/p>\n<ol>\n<li data-start=\"884\" data-end=\"1270\">The Law of Inertia (First Law)<\/li>\n<li data-start=\"884\" data-end=\"1270\"><strong>The Law of Acceleration (<\/strong>Second Law<strong>)<\/strong> unbalanced force changes the momentum of an object. Momentum is defined as p=mv, (where m is mass and v is velocity). The rate of change of momentum is proportional to the force applied. Mathematically, the law is: F=ma or F = m(v-u)\/t<\/li>\n<li data-start=\"884\" data-end=\"1270\">The Law of Action-Reaction (Third Law): To every action, there is an equal and opposite reaction.<\/li>\n<\/ol>\n<p data-start=\"1468\" data-end=\"1492\"><strong data-start=\"1472\" data-end=\"1492\">Inertia and Mass &#8211; <\/strong>Inertia is the resistance of an object to changes in motion and depends on mass. Heavier objects have more inertia. i.e. A train resists motion more than a cart<\/p>\n<p data-start=\"1468\" data-end=\"1492\">Newton deduced that if Earth can attract an apple, it can also attract the moon. This led to the idea of <strong data-start=\"738\" data-end=\"759\">centripetal force<\/strong>, which keeps objects moving in a circular path.<\/p>\n<p data-start=\"809\" data-end=\"952\"><strong data-start=\"809\" data-end=\"857\">Universal Law of Gravitation<\/strong> states that <strong data-start=\"870\" data-end=\"930\">every object in the universe attracts every other object<\/strong> with a force that is: The formula is F = G (M \u00d7 m) \/ d<sup>2<\/sup>, Where, F = gravitational force, G = universal gravitational constant, M, \ud835\udc5a = masses of two objects, d = distance between the centers of the two objects<\/p>\n<ul data-start=\"953\" data-end=\"1085\">\n<li><strong data-start=\"955\" data-end=\"980\">Directly proportional<\/strong> to the product of their masses.<\/li>\n<li><strong data-start=\"1015\" data-end=\"1041\">Inversely proportional<\/strong> to the square of the distance between them.<\/li>\n<\/ul>\n<p data-start=\"352\" data-end=\"678\"><strong data-start=\"352\" data-end=\"387\">Acceleration due to gravity (g)<\/strong> is caused by the gravitational force exerted by Earth. It is a constant near the Earth\u2019s surface, approximately <strong data-start=\"500\" data-end=\"512\">9.8 m\/s\u00b2<\/strong>, and is calculated using the formula: <span class=\"katex\"><span class=\"katex-mathml\">g=GM\/r\u00b2<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist-s\">\u200b (<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span>where <strong data-start=\"590\" data-end=\"595\">G<\/strong> is the gravitational constant, <strong data-start=\"627\" data-end=\"632\">M<\/strong> is Earth&#8217;s mass, and <strong data-start=\"654\" data-end=\"659\">R<\/strong> is Earth&#8217;s radius)<\/p>\n<ul>\n<li data-start=\"682\" data-end=\"782\">According to Newton&#8217;s Second Law, the gravitational force <strong data-start=\"740\" data-end=\"745\">F<\/strong> on a mass <strong data-start=\"756\" data-end=\"761\">m<\/strong> is: <span class=\"katex\"><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">F<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord mathnormal\">m<\/span><span class=\"mord mathnormal\">g<\/span><\/span><\/span><\/span><\/li>\n<li data-start=\"682\" data-end=\"782\">Weight is the force of attraction by gravity and depends on the location. W=mg<\/li>\n<li data-start=\"682\" data-end=\"782\">On the Moon, gravity is weaker. An object\u2019s weight is 1\/6th of its weight on Earth.<\/li>\n<\/ul>\n<p><strong>Mass and Weight<\/strong> &#8211; Mass is a measure of the amount of matter in an object, whereas weight is the force with which an object is attracted toward the Earth due to gravity.<\/p>\n<p><strong>Thrust and Pressure<\/strong> &#8211; thrust (force applied perpendicular to a surface) and pressure (thrust per unit area), A smaller area experiences greater pressure for the same force. The unit of pressure is Pascal (Pa).<\/p>\n<p><strong>Buoyancy and Archimedes&#8217; Principle<\/strong><\/p>\n<p>when an object is immersed in water, it experiences an upward force called the <strong>buoyant force<\/strong>. Whether an object sinks or floats depends on the balance between this buoyant force and its weight. If the weight is greater than the buoyant force, it sinks (like an iron nail); if lesser, it floats (like a plastic bottle or cork). The principle of buoyancy was discovered by Archimedes.<\/p>\n<p>Archimedes\u2019 Principle is introduced, which states that a body fully or partially immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by it.<\/p>\n<hr \/>\n<p><span style=\"color: #ff0000;\"><strong>Related Links<\/strong><\/span><\/p>\n<ul>\n<li><strong>General Science : Questions for Competitive Exams<\/strong> \ud83d\udd17<\/li>\n<\/ul>\n<p><strong><a href=\"https:\/\/thequickknowledge.com\/exam\/general-science\/\">General Science<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/study-materials\/\">Study Materials<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/current-affairs\/\">Current Affairs<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/practice-questions\/\">Practice Questions<\/a>,\u00a0<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Motion, Force, and Gravitation Relate to Mass &amp; Weight An object may appear to be at rest or in motion depending on the observer\u2019s frame of reference. For example, passengers inside a moving bus see each other at rest, but an observer outside sees them in motion. Types of Motion : Straight-line motion Circular motion [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"no-sidebar","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":"disabled","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","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":[137],"tags":[138],"class_list":["post-3419","post","type-post","status-publish","format-standard","hentry","category-general-science","tag-general-science-notes"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3419","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/comments?post=3419"}],"version-history":[{"count":10,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3419\/revisions"}],"predecessor-version":[{"id":3444,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3419\/revisions\/3444"}],"wp:attachment":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/media?parent=3419"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/categories?post=3419"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/tags?post=3419"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}