# Essay On Air Pressure

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Pressure is defined as the force acting per unit area of the surface. From equation (1), we can say that pressure is inversely proportional to area provided the force that acts on the area is constant. Pressure directly proportional to force provided the area on which the force acts is constant. # Atmospheric Pressure Pressure exerted by the atmospheric air is called atmospheric pressure. This is also termed as standard atmospheric pressure or normal pressure. The normal pressure is the pressure exerted by 760 mm long column of mercury at 0oC at sea level and at a altitude of 45o. It is equal to 1.01 105Nm-2. # Some consequences of pressure All cutting and piercing tools such as scissors, needles, knives, etc. have sharp edges. This is because…show more content…
A body floats in a liquid only when the weight of the body is equal to the upthrust acting on it. This is called principle of floatation. It can also be applied in gas. It can only be applied in liquid. # Force and Pressure Force Pressure It is an external agency that changes or tends to change the state of motion or state of rest of a body in a straight line. Normal force per unit area acting on a surface is called pressure. Its SI unit is Newton (N). Its SI unit is N/m² or Pascal (Pa). It is a vector quantity. It is a scalar quantity. It is measured by spring balance. It is measured by manometer, barometer and press guage,etc. # Upthrust and Pressure Upthrust Pressure When a body is partially or wholly immersed in a liquid, the resultant force acted on it by the liquid is called up-thrust. Normal force per unit area acting on a surface is called pressure. Its SI unit is Newton (N) Its SI unit Pascal