[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-139416-105":59,"doc-detail-139416-en":134},{"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":127,"head_meta":129,"extra_data":131,"updated_unix":133},105,"en","gravitational-fields-chapter-13-gravitational-field-and-potential","Gravitational fields - Chapter 13 - Gravitational field and potential","","Gravitational fields explains how gravity arises between masses and how to define a gravitational field as the region where a mass experiences force due to another mass. It derives gravitational field strength g, states its SI units, and describes field lines as always attractive. The section connects Newton’s law of gravitation to orbits, including the geostationary criteria. It further derives the gravitational field for a point mass and relates gravitational potential to work done per unit mass.",{"@graph":69,"@context":126},[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":20,"@type":76,"position":81},"https://docshare.wps.com/document/exam/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/gravitational-fields-chapter-13-gravitational-field-and-potential/139416/",{"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/gravitational-fields-chapter-13-gravitational-field-and-potential/139416.png","ImageObject",300,407,{"name":92,"@type":93},"Theodora","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-09-20","2026-08-24",true,{"@type":102,"interactionType":103,"userInteractionCount":29},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118,122],{"name":109,"@type":110,"acceptedAnswer":111},"What is a gravitational field and how is gravitational field strength defined?","Question",{"text":112,"@type":113},"A gravitational field is a region of space where a mass experiences a force due to gravitational attraction. Gravitational field strength g at a point is the force due to gravity (weight) per unit mass (g = Fg/m).","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How are gravitational field lines different from electric and magnetic field lines?",{"text":117,"@type":113},"Gravitational field lines indicate direction, but they are always attractive. They are never repulsive.",{"name":119,"@type":110,"acceptedAnswer":120},"How does Newton’s law relate to gravitational force and orbital motion?",{"text":121,"@type":113},"Newton’s law states that the gravitational force between two point masses is proportional to the product of the masses and inversely proportional to the square of their separation. For a planet in orbit, centripetal force balances gravitational force (FC = FG).",{"name":123,"@type":110,"acceptedAnswer":124},"What is gravitational potential and how is it connected to gravitational potential energy?",{"text":125,"@type":113},"Gravitational potential is the work done per unit mass to bring a test mass from infinity to a point. It is related to gravitational potential energy (GPE), with ɸ behaving like GPE per kg.","https://schema.org",{"og:url":83,"og:type":128,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":130,"canonical":83},"index,follow",{"doc_id":132,"site_id":62},139416,1787535149,{"code":4,"msg":5,"data":135},{"doc_id":132,"user_id":136,"nickname":92,"user_avatar":137,"doc_module":4,"category_id":19,"category_name":20,"doc_title":65,"doc_description":67,"doc_content":138,"file_id":139,"file_url":140,"file_type":141,"file_size":142,"view_count":29,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":29,"language":143,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":144,"faqs":145,"seo_title":146,"seo_description":67,"update_tm":133,"read_time":147},687197207919,"https://ap-avatar.wpscdn.com/avatar/a000253d6f5f7c60be?x-image-process=image/resize,m_fixed,w_180,h_180&k=1779446848396160552","13 Gravitational fields  \n13.1 Gravitational field  \n• When two or more masses are in proximity with each other there is an attractive force between them.  \n• This force is called gravity  \n• A gravitational field is defined as a region of space where a mass experience a force due to the gravitational attraction of another mass.  \n• The SI unit for gravitational field strength is N kg-1 or ms-2  \n• The gravitational field strength (g) at a point is the force due to gravity or weight (Fg) per unit mass (m) of an object at that point:  \nFgg =  \nm  \n• The larger the planet, the larger the g!  \n• Gravitational field lines like magnetic and electric field lines gives us an indication to their direction.  \n• Unlike the other two however, gravitational field lines are always attractive and never repulsive!  \n• Below are some examples of gravitational field lines  \n13.2 Gravitational force between point masses  \n• For a point outside a uniform sphere, the mass of the sphere may be considered to be a point mass at its centre.  \n• A uniform sphere is one where its mass is distributed evenly.  \n• The gravitational field lines around a uniform sphere are therefore identical to those around a point mass  \n• An object can be regarded as point mass when a body covers a very large distance as compared to its size.  \n• Radial fields are considered non-uniform fields.  \n• Hence g is different depending on how far you are from the centre of mass of the sphere  \n• Newton’s Law of Gravitation states that the gravitational force between two point masses is proportional to the product of the masses and inversely proportional to the square of their separation.  \n• This can be written as  \n􀜨􀯀 = 􀜩~~ ~~􀝉􀝎12􀝉2  \n• Here G is Newton’s gravitational constant 6.67 x 10-11 Nm2 kg-2  \n• This value will be given in exam.  \n• In order for a planet to stay in orbit around the sun (as oppose to falling into the sun!) the planet must travel in a circular orbit around the sun in order for centripetal force to balance the gravitational force  \nFC = FG  \n􀝉2 􀝒2􀯧   􀜩􀝉1 􀝉2 =  \n􀝎 􀝎 2  \n􀝒2􀯧 = 􀜩~~ ~~􀝉􀝎1  \n• The equation above proves that all planets travel at same tangential speed (vt) around the sun since the speed is only dependent on the mass of the sun (m 1)  \n• Most satellites orbiting the earth follow a geostationary orbit.  \n• The criteria for geostationary orbit are:  \n-Remains directly above the equator  \n-Moves from west to east (same direction as the Earth spins)  \n-Has an orbital time period equal to Earth’s rotational period of 24 hours  \n13.3 Gravitational field of a point mass  \n• In A levels the candidate must be able to derive the gravitational field equation  \n􀡳􀢓􀫚􀢍 =  \n􀢘 􀫛  \n• To derive the equation above first take Newton’s law of gravitation force equation  \n􀜩􀝉1􀝉2  \n􀜨􀯀 = 􀝎 2  \nAnd substitute FG with  \nFG = m2g  \n• g here is the same as acceleration due to gravity that you have been using!  \n• The SI unit is in N kg-1 or ms-1  \n• Based on the gravitational field equation, g is directly proportional to the mass of the planet (m 1) and inversely proportional to the square of the radius of the planet r2  \n• The value of g changes very little for small changes in height near the surface of the Earth (9 .81 ms-2) .  \n• This is because any height change is very small compared to the radius of the earth (r)  \n13.4 Gravitational potential  \n• Recall that gravitational potential energy (GPE) is given by  \nGPE = mgh  \n• It is defined as the energy an object possess due to its position in a gravitational field  \n• We can replace the height (h) with the distance from the center of the earth  \n(r) and mass (m) with the mass of the object above the earth (m2)  \nGPE = m2gr  \n• Gravitational potential (ɸ) is defined work done per unit mass in bringing a test mass from infinity to a defined point  \n• So basically, gravitational potential (ɸ) is just GPE per kg-1 (GPE/mass)!  \n• The SI unit is J kg-1  \n• Divide the equation above with m2  \nɸ = gr  \nRecall that  \n􀝃 =  \n􀜩􀝉1 ","cbCaidJtibUHENQq","https://ap.wps.com/l/cbCaidJtibUHENQq","pdf",563941,"English","# 13 Gravitational fields\n## 13.1 Gravitational field\n## 13.2 Gravitational force between point masses\n## 13.3 Gravitational field of a point mass\n## 13.4 Gravitational potential","[{\"question\":\"What is a gravitational field and how is gravitational field strength defined?\",\"answer\":\"A gravitational field is a region of space where a mass experiences a force due to gravitational attraction. Gravitational field strength g at a point is the force due to gravity (weight) per unit mass (g = Fg/m).\"},{\"question\":\"How are gravitational field lines different from electric and magnetic field lines?\",\"answer\":\"Gravitational field lines indicate direction, but they are always attractive. They are never repulsive.\"},{\"question\":\"How does Newton’s law relate to gravitational force and orbital motion?\",\"answer\":\"Newton’s law states that the gravitational force between two point masses is proportional to the product of the masses and inversely proportional to the square of their separation. For a planet in orbit, centripetal force balances gravitational force (FC = FG).\"},{\"question\":\"What is gravitational potential and how is it connected to gravitational potential energy?\",\"answer\":\"Gravitational potential is the work done per unit mass to bring a test mass from infinity to a point. It is related to gravitational potential energy (GPE), with ɸ behaving like GPE per kg.\"}]","Gravitational fields - Chapter 13 - Gravitational field and potential | PDF",15]