{"id":3961,"date":"2023-01-09T10:42:32","date_gmt":"2023-01-09T10:42:32","guid":{"rendered":"https:\/\/8thclass.deltapublications.in\/?page_id=3961"},"modified":"2025-08-19T09:26:52","modified_gmt":"2025-08-19T09:26:52","slug":"s-12-c-friction-a-necessary-evil","status":"publish","type":"page","link":"https:\/\/8thclass.deltapublications.in\/index.php\/s-12-c-friction-a-necessary-evil\/","title":{"rendered":"s-12.c Friction: A Necessary Evil"},"content":{"rendered":"\n<h2 class=\"wp-block-heading has-text-align-center has-text-color\" style=\"color:#00056d;text-transform:uppercase\"><strong>Friction: A Necessary Evil<\/strong><\/h2>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<div style=\"position: relative; width: 100%; height: 0; padding-top: 56.2500%;\n padding-bottom: 0; box-shadow: 0 2px 8px 0 rgba(63,69,81,0.16); margin-top: 1.6em; margin-bottom: 0.9em; overflow: hidden;\n border-radius: 8px; will-change: transform;\">\n  <iframe loading=\"lazy\" style=\"position: absolute; width: 100%; height: 100%; top: 0; left: 0; border: none; padding: 0;margin: 0;\"\n    src=\"https:\/\/www.canva.com\/design\/DAF6xfCKRO8\/WYf3EehOriCWqMbHDIWHqQ\/watch?embed\" allowfullscreen=\"allowfullscreen\" allow=\"fullscreen\">\n  <\/iframe>\n<\/div>\n<a href=\"https:&#x2F;&#x2F;www.canva.com&#x2F;design&#x2F;DAF6xfCKRO8&#x2F;WYf3EehOriCWqMbHDIWHqQ&#x2F;watch?utm_content=DAF6xfCKRO8&amp;utm_campaign=designshare&amp;utm_medium=embeds&amp;utm_source=link\" target=\"_blank\" rel=\"noopener\">A Necessary Evil<\/a> by Delta publications\n<\/div>\n<\/div>\n\n\n\n<p class=\"has-text-color has-link-color has-huge-font-size wp-elements-28d136ae4331e7eb05ec8e1cb71ebcde\" style=\"color:#74008b\">key notes :<\/p>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-3c1dffac685444200b48c506d707e881\" style=\"color:#000060\"><strong>Definition of Friction<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li>Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-e1f7e346cce2906eb11b4a1c70ab1e21\" style=\"color:#000060\"><strong>Types of Friction<\/strong>:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105745.361-1024x579.png\" alt=\"\" class=\"wp-image-21061\" style=\"width:552px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105745.361-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105745.361-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105745.361-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105745.361.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Static Friction<\/strong>: The frictional force that prevents two surfaces from sliding past each other.<\/li>\n\n\n\n<li><strong>Kinetic (Sliding) Friction<\/strong>: The frictional force acting between moving surfaces.<\/li>\n\n\n\n<li><strong>Rolling Friction<\/strong>: The frictional force that occurs when an object rolls over a surface.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-2fb4f7f0844882e6d7449eb6e55ed84f\" style=\"color:#000060\"><strong>Causes of Friction<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Surface Roughness<\/strong>: Microscopic irregularities on surfaces cause friction.<\/li>\n\n\n\n<li><strong>Molecular Attraction<\/strong>: Intermolecular forces between the surfaces in contact contribute to friction.<\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105852.441-1024x579.png\" alt=\"\" class=\"wp-image-21062\" style=\"width:471px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105852.441-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105852.441-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105852.441-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105852.441.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-855bf762432d343390408257dc6c11fa\" style=\"color:#000060\"><strong>Advantages of Friction<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Walking<\/strong>: Friction between shoes and the ground allows us to walk without slipping.<\/li>\n\n\n\n<li><strong>Transportation<\/strong>: It enables vehicles to move and stop effectively (brakes rely on friction).<\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105958.569-1024x579.png\" alt=\"\" class=\"wp-image-21063\" style=\"width:483px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105958.569-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105958.569-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105958.569-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T105958.569.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Holding Objects<\/strong>: Friction allows us to grip and hold objects.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-cf6404d15f0e4180ef34b6d195dc836b\" style=\"color:#000060\"><strong>Disadvantages of Friction<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Wear and Tear<\/strong>: Friction causes wear and damage to machinery and moving parts.<\/li>\n\n\n\n<li><strong>Energy Loss<\/strong>: Friction converts useful kinetic energy into heat, leading to energy loss.<\/li>\n\n\n\n<li><strong>Reduced Efficiency<\/strong>: In engines and machines, friction reduces efficiency by generating heat.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-1336b692b371966a9ae24b43611505e9\" style=\"color:#000060\"><strong>Friction as a Necessary Evil<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Balancing Act<\/strong>: While friction can cause problems like wear and energy loss, it is also essential for many everyday activities and functions.<\/li>\n\n\n\n<li><strong>Control of Friction<\/strong>: Using lubricants, polishing surfaces, and using wheels can reduce unwanted friction. However, sometimes friction is increased (e.g., using sand on icy roads) to prevent slipping.<\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110327.509-1024x579.png\" alt=\"\" class=\"wp-image-21065\" style=\"width:454px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110327.509-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110327.509-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110327.509-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110327.509.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-ab0cd34df59a5a5b5d7739db925434a1\" style=\"color:#000060\"><strong>Real-life Applications<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Brake Systems<\/strong>: Car brakes use friction to stop the vehicle.<\/li>\n\n\n\n<li><strong>Walking on Ice<\/strong>: People use shoes with better grip to increase friction and prevent slipping on icy surfaces.<\/li>\n\n\n\n<li><strong>Sports<\/strong>: Athletes use specialized shoes to increase or decrease friction depending on the sport (e.g., spikes for running, smooth soles for bowling).<\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110443.404-1024x579.png\" alt=\"\" class=\"wp-image-21066\" style=\"width:474px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110443.404-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110443.404-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110443.404-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110443.404.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-5bd18c965748b404819e8b6c920a3b01\" style=\"color:#000060\"><strong>Measuring Friction<\/strong>:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"579\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110543.011-1024x579.png\" alt=\"\" class=\"wp-image-21068\" style=\"width:457px;height:auto\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110543.011-1024x579.png 1024w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110543.011-300x170.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110543.011-768x434.png 768w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2025\/08\/Untitled-design-2025-08-12T110543.011.png 1472w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li>The coefficient of friction (\u03bc) is a value that represents the ratio of the force of friction between two bodies and the force pressing them together.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-6dc7c050c4fc3a3a0957e2635811be48\" style=\"color:#000060\"><strong>Friction in Technology<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li><strong>Bearings<\/strong>: Devices like ball bearings reduce friction in machinery, making them more efficient.<\/li>\n\n\n\n<li><strong>Aerodynamics<\/strong>: Engineers design vehicles with streamlined shapes to reduce air resistance (a form of friction).<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-link-color has-large-font-size wp-elements-951fe2609f443129cbcfc13e95a0ec0e\" style=\"color:#000060\"><strong>Conclusion<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list has-large-font-size\">\n<li>Friction is unavoidable but essential. It is important to understand how to manage and utilize it effectively to maximize benefits and minimize drawbacks in various applications.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-color has-large-font-size\" style=\"color:#d90000\"><strong>Let&#8217;s practice!<\/strong><\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/95745\/255\/690\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-114.png\" alt=\"\" class=\"wp-image-7867\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-114.png 500w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-114-300x300.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-114-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/77049\/492\/210\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-113.png\" alt=\"\" class=\"wp-image-7868\" srcset=\"https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-113.png 500w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-113-300x300.png 300w, https:\/\/8thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-113-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Friction: A Necessary Evil A Necessary Evil by Delta publications key notes : Definition of Friction: Types of Friction: Causes of Friction: Advantages of Friction: Disadvantages of Friction: Friction as a Necessary Evil: Real-life Applications: Measuring Friction: Friction in Technology: Conclusion: Let&#8217;s practice!<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-3961","page","type-page","status-publish","hentry","entry"],"aioseo_notices":[],"_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3961","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/comments?post=3961"}],"version-history":[{"count":24,"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3961\/revisions"}],"predecessor-version":[{"id":21246,"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3961\/revisions\/21246"}],"wp:attachment":[{"href":"https:\/\/8thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/media?parent=3961"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}