{"id":6256,"date":"2020-10-13T15:17:01","date_gmt":"2020-10-13T09:47:01","guid":{"rendered":"http:\/\/astan.lk\/al_virtualclassroom\/?p=6256"},"modified":"2020-10-13T15:17:56","modified_gmt":"2020-10-13T09:47:56","slug":"hydrostatics","status":"publish","type":"post","link":"https:\/\/astan.lk\/al_virtualclassroom\/hydrostatics\/","title":{"rendered":"Hydrostatics"},"content":{"rendered":"<p><b>Hydrostatics<\/b>\u00a0is the branch of fluid mechanics that studies incompressible fluids at rest.<\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Density<\/strong><\/span><\/p>\n<p>The <b>density\u00a0<\/b>\u00a0of a substance is its mass per unit volume. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/ds.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7920\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/ds.png\" alt=\"ds\" width=\"134\" height=\"97\" \/><\/a><\/p>\n<p><strong><span style=\"text-decoration: underline;\">Relative density<\/span><\/strong><\/p>\n<p>the ratio of the density of a substance to the density of a standard, usually water for a liquid.<\/p>\n<p><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/rd.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7921\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/rd.png\" alt=\"rd\" width=\"265\" height=\"156\" \/><\/a><\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Pressure in a static fluid<\/strong><\/span>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 When a fluid is at rest , a force only acts at right angles.This is because a fluid cannot sustain \u00a0a tangental force .When a fluid at rest forces simply act normal to the surface .<\/p>\n<dl>\n<dd><span class=\"mwe-math-element\"><img decoding=\"async\" class=\"mwe-math-fallback-image-inline\" src=\"https:\/\/wikimedia.org\/api\/rest_v1\/media\/math\/render\/svg\/b2f127feccc050bed7157fa2e0176bdcda790951\" alt=\"p={\\frac {F}{A}}\" \/><\/span><\/dd>\n<\/dl>\n<p>where\u00a0<span class=\"mwe-math-element\"><img decoding=\"async\" class=\"mwe-math-fallback-image-inline\" src=\"https:\/\/wikimedia.org\/api\/rest_v1\/media\/math\/render\/svg\/81eac1e205430d1f40810df36a0edffdc367af36\" alt=\"p\" \/><\/span> is the pressure,<span class=\"mwe-math-element\"><img decoding=\"async\" class=\"mwe-math-fallback-image-inline\" src=\"https:\/\/wikimedia.org\/api\/rest_v1\/media\/math\/render\/svg\/545fd099af8541605f7ee55f08225526be88ce57\" alt=\"F\" \/><\/span> is the normal force,<span class=\"mwe-math-element\"><img decoding=\"async\" class=\"mwe-math-fallback-image-inline\" src=\"https:\/\/wikimedia.org\/api\/rest_v1\/media\/math\/render\/svg\/7daff47fa58cdfd29dc333def748ff5fa4c923e3\" alt=\"A\" \/><\/span> is the area of the surface on contact.<\/p>\n<p>Pressure is a scalar quantity ,it has no fixed directions.The direction of the force exerted by the liquid is decided by the orientation of area present to the liquid.<\/p>\n<p><strong><span style=\"text-decoration: underline;\">Expression for fluid pressure<\/span><\/strong><\/p>\n<h4><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7922\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/fp2.gif\" alt=\"fp2\" width=\"500\" height=\"211\" \/>\u00a0If we consider atmospheric pressure , say it&#8217;s P<sub>o<\/sub> , then the pressure at depth h is given by \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <strong>P = P<sub>o<\/sub> + h\u03c1g<\/strong><\/h4>\n<p>In a static liquid, pressures at same level in a same liquid are equal. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/pr.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7923\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/pr.gif\" alt=\"pr\" width=\"334\" height=\"93\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/prs.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7924\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/prs.png\" alt=\"prs\" width=\"542\" height=\"124\" \/><\/a><\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Pressure of atmosphere<\/strong><\/span><\/p>\n<p>Our Earth is surrounded by air upto a considerable height.This envelope of air surrounding the Earth is called atmosphere.Since air has weight, a column of air is capable of exerting pressure.It is first measured by Toricelli.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/encrypted-tbn0.gstatic.com\/images?q=tbn:ANd9GcQjd0dQ6CFeq16cYw3cJzkZ0W5g53lFt_Il6TNtSEYMQvDG5jMQ\" alt=\"Image result for simple barometer\" \/>\u00a0 \u00a0 <strong>\u00a0 \u00a0 \u00a0 \u00a0Atmospheric pressure P<sub>o<\/sub>\u00a0= h\u03c1g<\/strong><\/p>\n<p>1 atm=1.014 bar= 760 mmHg \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a01 torr = 1mmHg<\/p>\n<p><strong><span style=\"text-decoration: underline;\">Manometer<\/span><\/strong> \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Manometer consist of U tube, it is used to find the difference in pressures between the gas enclosed in a vessel and atmospheric pressure.<\/p>\n<p><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/mn.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-7926 alignleft\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/mn.png\" alt=\"mn\" width=\"628\" height=\"225\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Pressure at x = Pressure at y \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/11.1.1.png\"><br \/>\n<\/a>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Unknown Pressure\u00a0<strong>P = P<sub>o<\/sub> + h\u03c1g<\/strong><\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Determination of density of coconut oil using U tube<\/strong><\/span><\/p>\n<p>First take the water in the U tube then add coconut oil to one of the arm and give some time to settle.After it settles measure the height of coconut oil(h2) and water(h1) from common interface. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0To take several measurements add coconut oil and measure the heights from the common interface.<\/p>\n<p><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/hs.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7929\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/hs.png\" alt=\"hs\" width=\"902\" height=\"862\" \/><\/a><\/p>\n<ul>\n<li>First take water and then take coconut oil.Otherwise coconut oil floats in both arms of U tube.<\/li>\n<li>To take several readings we have to add less dense liquid for corresponding arm otherwise always h1 and h2 will be same.<\/li>\n<li>For miscible liquids we cannot use the above method.<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline;\"><strong>Hare&#8217;s apparatus<\/strong><\/span><\/p>\n<p><strong><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/ha.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7977\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/ha.png\" alt=\"ha\" width=\"455\" height=\"356\" \/><\/a><\/strong>P0 &#8211; atmospheric pressure<\/p>\n<p>Arrange the above setup as shown in the figure .Suck the air from the tube,then the liquids in both arm rises upto maximum level.Then measure the heights hw and hl.Then reduce heights and take several sets of reading.<\/p>\n<p><a href=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/hra.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-7985\" src=\"http:\/\/astan.lk\/al_virtualclassroom\/wp-content\/uploads\/2017\/01\/hra.png\" alt=\"hra\" width=\"462\" height=\"446\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<h3><span style=\"text-decoration: underline;\">Pascal&#8217;s law<\/span><\/h3>\n<p><b>Pascal&#8217;s law<\/b> \u00a0states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.<\/p>\n<p>Incompressible fluid means due to the pressure the density of the fluid<\/p>\n<p>&nbsp;<\/p>\n<p>The pressure acting on both pistons in a hydraulic jack is equal.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" title=\"hydraulic lift\" src=\"http:\/\/docs.engineeringtoolbox.com\/documents\/1274\/hydraulic_lift.png\" alt=\"hydraulic lift\" width=\"300\" height=\"213\" \/><\/p>\n<p>The force equation for the small cylinder \u00a0\u00a0<i>F<sub>s<\/sub> = p A<sub>s<\/sub>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/i><\/p>\n<p><i>where \u00a0<\/i><i>F<sub>s<\/sub> = force acting on the piston in the small cylinder (N) ,\u00a0<\/i><i>A<sub>s<\/sub> = area of small cylinder (m<sup>2<\/sup>) , \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<\/i><i>p = pressure in small and large cylinder\u00a0 (Pa, N\/m<sup>2<\/sup>)<br \/>\n<\/i><\/p>\n<p>The force equation for the large cylinder \u00a0 \u00a0\u00a0<i>F<sub>l<\/sub> = p A<sub>l<\/sub>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/i><\/p>\n<p><i>where \u00a0<\/i><i>F<sub>l<\/sub> = force acting on the piston in the large cylinder (N) ,\u00a0<\/i><i>A<sub>l<\/sub> = area of large cylinder (m<sup>2<\/sup>) , \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/i><i>p = pressure in small and large cylinder (Pa, N\/m<sup>2<\/sup>)<\/i><\/p>\n<p><i>F<sub>s<\/sub> \/ A<sub>s <\/sub>= F<sub>l<\/sub> \/ A<sub>l\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <\/sub><sub><br \/>\n<\/sub><\/i><\/p>\n<p>or<\/p>\n<p><i>F<sub>s<\/sub> = F<sub>l<\/sub> A<sub>s <\/sub>\/ A<sub>l\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<\/sub>\u00a0<\/i><\/p>\n<p>&nbsp;<\/p>\n<h3><span style=\"text-decoration: underline;\">Upthrust<\/span><\/h3>\n<p>&nbsp;<\/p>\n<ul>\n<li>A fluid will exert a <b>force upward<\/b> on a body if it is partly or wholly submerged within it. This is because the deeper into a fluid you go, the greater the weight of it and so the greater the pressure. This difference in pressure between the top and the bottom of the object produces an upward force on it. This is called <b>Upthrust<\/b>.<\/li>\n<li>\n<div id=\"ch_6\" class=\"holder\">\n<ul>\n<li>According to <b>Archimedes&#8217; Principle<\/b>, the upthrust on an object in a fluid is equal to the <b>weight of the fluid displaced<\/b>.<\/li>\n<\/ul>\n<\/div>\n<div id=\"ch_7\" class=\"holder\">\n<div class=\"definition\">\n<div class=\"definition_inner\"><b>Upthrust = Weight of Fluid Displaced = mg = v\u03c1g<\/b><\/div>\n<div class=\"definition_inner\"><strong>Upthrust = v\u03c1g<\/strong><\/div>\n<\/div>\n<\/div>\n<div class=\"definition_inner\"><\/div>\n<\/li>\n<\/ul>\n<h3><span style=\"text-decoration: underline;\">Archimede&#8217;s principle<\/span><\/h3>\n<p>It states that when a body is fully or partially emerged in an incompressible fluid at rest, it experiences an upward force equal to the weight of the fluid displaced.<\/p>\n<p>When an object is placed on the surface of a liquid it will either float or sink. This depends upon two forces:<\/p>\n<ul>\n<li>The weight W<sub>1<\/sub> acting vertically downwards, which is due to the gravitational pull of the earth<\/li>\n<\/ul>\n<ul>\n<li>Upthrust \u00a0acting vertically upwards, which is equal to the weight of the liquid displaced by the object W<sub>2<\/sub>.<\/li>\n<\/ul>\n<p>You know that the weight of an object is the product of its volume and its density. Hence,<\/p>\n<p>W<sub>1<\/sub> = Volume of the object (V) x Density of the object (d<sub>1<\/sub>)<\/p>\n<p>W<sub>2<\/sub> = Volume of the liquid displaced (V) x Density of the liquid (d<sub>2<\/sub>)<\/p>\n<p>Let us see what are the different situations under which a body floats, sinks or remains submerged completely at any level in the liquid.<\/p>\n<p><strong>Case 1:<\/strong><\/p>\n<p>When the weight of the object W<sub>1<\/sub> is equal to the weight of the liquid displaced W<sub>2<\/sub>, the object will stay in the position of rest completely immersed in the liquid. Here,<\/p>\n<p>W<sub>1<\/sub> = W<sub>2<\/sub> or<\/p>\n<p>V x d<sub>1<\/sub> = V x d<sub>2<\/sub> or d<sub>1<\/sub> = d<sub>2<\/sub>, then the object will be floating completely immersed in a liquid as shown in figure below.<\/p>\n<h5 class=\"contentimage\"><img loading=\"lazy\" decoding=\"async\" title=\"condition for suspension of an object in water\" src=\"http:\/\/images.tutorvista.com\/content\/fluids-pressure\/block-suspension-condition.gif\" alt=\"\" width=\"188\" height=\"161\" align=\"middle\" \/><\/h5>\n<p>Weight of the object is equal to the weight of the liquid<\/p>\n<p><strong>Case 2:<\/strong><\/p>\n<p>When the weight of the object is greater than the weight of the displaced liquid, the object will sink. Here,<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img111.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img112.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img113.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p>Thus, when the density of the object is greater than the density of the liquid, the object will sink.<\/p>\n<h5 class=\"contentimage\"><img loading=\"lazy\" decoding=\"async\" title=\"block sinks when its density is greater than liquid\" src=\"http:\/\/images.tutorvista.com\/content\/fluids-pressure\/block-sinking-condition.gif\" alt=\"\" width=\"188\" height=\"161\" align=\"middle\" \/><\/h5>\n<p>Weight of the object is greater than the weight of the liquid displaced.<\/p>\n<p><strong>Case 3:-<\/strong><\/p>\n<p>When the weight of the object is less than the buoyant force (upthrust), the object will float on the surface of the liquid.<\/p>\n<p>When the object floats, only a part of it is submerged in the liquid and volume of the liquid displaced will be less than its own volume. Let V&#8217; be the volume of the liquid displaced by the submerged part of the object. Here<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img116.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img117.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img118.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.tutorvista.com\/contentimages\/physics_9\/content\/us\/class9physics\/chapter04\/images\/img119.gif\" alt=\"\" align=\"middle\" \/><\/p>\n<p>Density of the solid is less than the density of the liquid and hence the object will float.<\/p>\n<h5 class=\"contentimage\"><img loading=\"lazy\" decoding=\"async\" title=\"condition for floatation of an object in water\" src=\"http:\/\/images.tutorvista.com\/content\/fluids-pressure\/block-flotation-condition.gif\" alt=\"\" width=\"188\" height=\"161\" align=\"middle\" \/><\/h5>\n<p>Weight of the object is less than the weight of the liquid displaced<\/p>\n<h3><span style=\"text-decoration: underline;\">Hydrometer<\/span><\/h3>\n<p>Hydrometer is an instrument used for determining the density of a liquid. It usually consists of a glass float with a long thin stem which is graduated. The glass float is a large hollow bulb which increases the buoyancy so that the hydrometer floats. The narrow stem increases the sensitivity of the hydrometer. The bottom of the hydrometer is made heavier by loading it with lead shots so that it floats vertically.<\/p>\n<h5 class=\"contentimage\"><img loading=\"lazy\" decoding=\"async\" class=\"\" title=\"hydrometer to test the density of a liquid\" src=\"http:\/\/images.tutorvista.com\/content\/fluids-pressure\/hydrometer.gif\" alt=\"hydrometer to test the density of a liquid\" width=\"162\" height=\"254\" align=\"middle\" \/><\/h5>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Hydrostatics\u00a0is the branch of fluid mechanics that studies incompressible fluids at rest. Density The density\u00a0\u00a0of a substance is its mass per unit volume. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 [&hellip;]<\/p>\n","protected":false},"author":842,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[16,1948],"tags":[],"class_list":["post-6256","post","type-post","status-publish","format-standard","hentry","category-physics","category-unit-02-en"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Hydrostatics - Learning &amp; Education Portal<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/astan.lk\/al_virtualclassroom\/hydrostatics\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Hydrostatics - Learning &amp; Education Portal\" \/>\n<meta property=\"og:description\" content=\"Hydrostatics\u00a0is the branch of fluid mechanics that studies incompressible fluids at rest. 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