{"id":10656,"date":"2020-12-18T09:31:03","date_gmt":"2020-12-18T04:01:03","guid":{"rendered":"https:\/\/cbselibrary.com\/?p=10656"},"modified":"2020-12-18T12:03:37","modified_gmt":"2020-12-18T06:33:37","slug":"understanding-pressure-in-liquids","status":"publish","type":"post","link":"https:\/\/cbselibrary.com\/understanding-pressure-in-liquids\/","title":{"rendered":"Understanding Pressure in Liquids"},"content":{"rendered":"
Figure shows an old container being hoisted from the sea. The water in the container flows out in all directions. This is because pressure<\/a> in a liquid acts in all directions<\/strong>. The man in Figure is not going to the outer space. Fie is actually a deep-sea diver wearing a magnesium alloy suit which can withstand high underwater pressure. This is because pressure in a liquid increases with depth<\/strong>. <\/p>\n Aim:<\/strong> To study factors affecting the pressure in a liquid. Observation:<\/strong> B. Relationship between Density and Pressure in a Liquid Conclusion:<\/strong> Example 1.\u00a0<\/strong>What will be the pressure in N\/m2<\/sup> at a depth of 1.5 m in brine of density 120 kg\/cm3<\/sup> ? Example 2.\u00a0<\/strong>Calculate the density of a liquid if the pressure at a point 30 m below its surface is 32 \u00d7 104\u00a0N\/m2<\/sup>. Example 3.<\/strong> Figure shows a submarine travelling from the surface of the sea to a depth of 6000 m. Example 4.<\/strong> Figure shows a farmer\u2019s ingenious method of drawing water from a pond located at a nearby hill by using a metal pipe. Water rushing out of the holes at the lower end of the pipe irrigates his plants. Example 5.<\/strong> Calculate the pressure exerted by the water retained by a dam at a depth of 60 m. Example 6.<\/strong> A scientist has invented a robot to work at the seabed. According to his calculation, the armour of the robot can withstand a maximum pressure of 106 Pa exerted by the sea water. If the density of sea water is 1025 kg m-3<\/sup>\u00a0and g = 9.8 N kg-1<\/sup>, what is the maximum depth of the seabed that this robot can work at? Understanding Pressure in Liquids Figure shows an old container being hoisted from the sea. The water in the container flows out in all directions. This is because pressure in a liquid acts in all directions. The man in Figure is not going to the outer space. Fie is actually a deep-sea diver wearing a magnesium … Read more<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[404],"tags":[3818,3820,3819,3817],"yoast_head":"\n
\n<\/p>\n
\n<\/p>\nFormula for Pressure in Liquids<\/strong><\/h3>\n
\n
\nP = h\u03c1g
\n<\/strong>where h is the depth, \u03c1\u00a0is the “density of the liquid and g is the gravitational field strength.
\n<\/li>\nApplications of Pressure in Liquids<\/strong><\/h3>\n
\n
\n<\/li>\n
\n<\/li>\n
\n<\/li>\n<\/ol>\nWays to Reduce the Negative Effects of Pressure in Liquids<\/strong><\/h3>\n
\n
\n<\/li>\n
\n<\/li>\n
\n<\/li>\nActivity<\/strong><\/h3>\n
\nMaterials:<\/strong> Water, alcohol, glycerine, a thin rubber sheet
\nApparatus:<\/strong> Manometer filled with coloured paraffin, rubber tube, thistle funnel, tall plastic bottle, metre rule, retort stand with clamp, rubber band
\nA. Relationship between Depth and Pressure in a Liquid
\nMethod:<\/strong><\/p>\n\n
\n<\/li>\n
\nIt is observed that when the value of h is increased, the value of l increases.
\nDiscussion:<\/strong><\/p>\n\n
\nMethod:<\/strong>
\nThe above activity is repeated by replacing water with alcohol (density 800 kg m-3) and then, with glycerine (density 1300 kg m-3<\/sup>).
\nObservation:<\/strong>
\nIt is observed that for a fixed value of h, the values of l is biggest for glycerine followed by water and then alcohol.
\nDiscussion:<\/strong><\/p>\n\n
\n(b) Given that \u03c1glycerine\u00a0<\/sub>> \u03c1water\u00a0<\/sub>> \u03c1alcohol \u00a0<\/sub>and from the observation lglycerine\u00a0<\/sub>> lwater\u00a0<\/sub>> lalcohol\u00a0<\/sub>we can conclude that the pressure of the liquid increases with density.<\/li>\n
\n1. The pressure in a liquid increases with depth.
\n2. The pressure in a liquid increases with density.<\/p>\nPressure in Liquids Example Problems with Solutions<\/strong><\/h3>\n
\nSolution: \u00a0\u00a0\u00a0<\/strong>P = h\u03c1g
\n=15 \u00d7 120 \u00d7 10
\n= 1800 N\/m2<\/sup><\/p>\n
\nSolution:<\/strong> \u00a0\u00a0\u00a0P = h\u03c1g
\n\\( \\Rightarrow d=\\frac{P}{hg} \\)
\n\\( =\\frac{32\\times {{10}^{4}}}{30\\times 10}=1066.6\\text{ kg\/}{{\\text{m}}^{3}} \\)<\/p>\n
\n
\nIf the density of sea water is 1025 kg m-3<\/sup>\u00a0and by taking g = 9.8 N kg-1<\/sup>, calculate the pressure exerted by the sea water on the submarine at that depth.
\nSolution:<\/strong>
\nUsing the formula P = h\u03c1g,
\nP = 6000 x 1025 x 9.8
\n= 6.03 x 107<\/sup> Pa<\/p>\n
\n
\nCalculate the pressure of the water rushing out of the holes. [Density of water = 103<\/sup> kg m-3<\/sup>; g = 9.8 N kg-1<\/sup>]
\nSolution:<\/strong>
\nPressure of water rushing out of the holes,
\nP = h\u03c1g = 16 x 103<\/sup> x 9.8
\n= 1.57 x 105<\/sup> Pa<\/p>\n
\n[Density of water = 1000 kg m-3<\/sup>; g = 9.8 N kg-1<\/sup>]
\nSolution:<\/strong>
\nUsing formula P = h\u03c1g
\nP = 60 x 1000 x 9.8
\n= 5.88 x 105<\/sup> Pa<\/p>\n
\nSolution:
\n
\n<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"