[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-657822-105":59,"doc-detail-657822-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","static-equilibrium-chapter-1-definition-and-free-body-diagram","Static Equilibrium - Chapter 1 - Definition and Free Body Diagram","","Static equilibrium describes an object at rest when the forces and moments acting on it balance. The resultant of both forces and moments equals zero, expressed through vector sums. The section introduces forces as vectors with magnitude and direction, explains what forces do, and derives the moment (torque) relation using perpendicular components. It also covers units for force and moment, and distinguishes cases like cable constraints and force couples. Finally, it presents a step-by-step method for constructing free-body diagrams to apply equilibrium equations.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/static-equilibrium-chapter-1-definition-and-free-body-diagram/657822/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/static-equilibrium-chapter-1-definition-and-free-body-diagram/657822.png","ImageObject",300,407,{"name":92,"@type":93},"naya.afterrain","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-26",true,{"@type":102,"interactionType":103,"userInteractionCount":24},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What conditions define static equilibrium?","Question",{"text":112,"@type":113},"An object in static equilibrium has balanced forces and moments, so the resultant of forces and the resultant of moments both equal zero.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How are forces and moments related in equilibrium equations?",{"text":117,"@type":113},"The equilibrium condition uses vector sums: the forces and the moments (torques) must each add to zero, allowing reaction forces and moments to be solved.",{"name":119,"@type":110,"acceptedAnswer":120},"How do you construct a correct free body diagram?",{"text":121,"@type":113},"Isolate the body, draw its external boundaries, replace removed contacts with applied forces, and choose coordinate axes and relevant dimensions without clutter so force arrows are clearly distinguished.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},657822,1793103447,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":24,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},962094248482,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","Static Equilibrium  \nStatic Equilibrium Definition:  \nWhen forces acting on an object which is at rest are balanced, then the object is in a state of static equilibrium.  \n- No translations  \n- No rotations  \nIn a state of static equilibrium, the resultant of the forces and moments equals zero . That is, the vector sum of the forces and moments adds to zero .  \nTolerances for optics are very tight. We need to support them so they are accurately located.  \nIf forces are applied, we want to determine: Motion  \nDistortion  \nIn order to do this, we need to evaluate the system, including the applied forces and thereaction forces .  \nIn this section, we define forces and moments, develop the free body diagram, and use the  \nequations of static equilibrium to solve for reaction forces and moments .  \nForces are vectors:  \nThey have a magnitude and direction .  \nWhat does a force do? Can accelerate an object F = m a Can stretch a spring scale  \nForces can be applied:  \nUnits of Pounds on Newtons  \n1 pound (lbF)= 4.45 N : 1 N = 0.22 lb  \nOr they can come for gravity  \nW = m g (g = 9.8 m/s2 = 386 in/s2) 1 kg has weigh of 9.8 N or 2.2 lbs  \n1 lbM is the mass that weighs 1 pound  \n1 slug weighs 32.2 lbs  \nThe moment is defined as A =  × B  \n= rAB FB sinθ  \n= r ⋅ FAB ⊥  \nAlso called “torque” = r⊥ ⋅ FB  \nUnits are in-lb or N-m 1 N-m = 8.84 in-Lb  \nMoments are “twisting forces”. They make things rotate  \nDefining moment from applied force  \n􀀪 􀀪  \nMA =  × FB  \n􀀪  \nF  \nB  \nMA = rAB  ⋅ F⊥  \nMA = r⊥ ⋅ F   \nr⊥ =   sin  \n􀀪  \nF  \nB  \nsinθ  \n􀀪  \nF  \nB  \nθ  \n􀀪  \nF  \nB  \nForce couples  \nTwo forces, equal and opposite in direction, which do not act in the same line cause a pure moment  \nM = F d  \nM = F d  \nF  \nF  \nF  \nF  \n Simple cases  \nCable  \nCan only transmit tension along direction of cable No compression  \nNo moment  \nNo lateral force  \nConstraints  \nConstraints are attachment points that will maintain their position.  \nIdealization of 2D supports  \nIdealization of 3D supports  \nFree Body Diagrams  \nStep 1. Determine which body or combination of bodies is to be isolated. The body chosen will usually involve one or more of the desired unknown quantities.  \nStep 2. Next, isolate the body or combination of bodies chosen with a diagram that represents its complete external boundaries.  \nStep 3. Represent all forces that act on the isolated body as applied by the removed contacting bodies in their proper positions in the diagram of the isolated body. Do not show the forces that the object exerts on anything else, since these forces do not affect the object itself.  \nStep 4. Indicate the choice of coordinate axes directly on the diagram. Pertinent dimensions may also be represented for convenience. Note, however, that the free-body diagram serves the purpose of focusing accurate attention on the action of the external forces; therefore, the diagram should not be cluttered with excessive information. Force arrows should be clearly distinguished from other arrows to avoid confusion.  \nWhen these steps are completed a correct free-body diagram will result. Now, the appropriate equations of equilibrium may be utilized to find the proper solution.","cbCaikzKGfELRVTg","https://ap.wps.com/l/cbCaikzKGfELRVTg","pdf",3496538,33,"English","# Static Equilibrium Definition\n## Forces and Moments\n## Free Body Diagrams","[{\"question\":\"What conditions define static equilibrium?\",\"answer\":\"An object in static equilibrium has balanced forces and moments, so the resultant of forces and the resultant of moments both equal zero.\"},{\"question\":\"How are forces and moments related in equilibrium equations?\",\"answer\":\"The equilibrium condition uses vector sums: the forces and the moments (torques) must each add to zero, allowing reaction forces and moments to be solved.\"},{\"question\":\"How do you construct a correct free body diagram?\",\"answer\":\"Isolate the body, draw its external boundaries, replace removed contacts with applied forces, and choose coordinate axes and relevant dimensions without clutter so force arrows are clearly distinguished.\"}]","Static Equilibrium - Chapter 1 - Definition and Free Body Diagram | PDF",1792991007,83]