At a depth of 1000 m in an ocean (a) What is theabsolute pressure ? (b)What is the gauge pressure ? © Find the force acting on the window of area 20cmxx20cm of a submarine at this depth the interior of which is maintained at sea level atmospheric pressure. (the density of sea water =1.03xx10^(3)xx10^(3)kgm^(-3),g=10ms^(-2))

At a depth of 1000 m in an ocean (a) What is theabsolute pressure ? (b

1.	At a depth of 1000 m in an ocean (a) What is theabsolute pressure ? (b)What is the gauge pressure ? © Find the force acting on the window of area 20cmxx20cm of a submarine at this depth the interior of which is maintained at sea level atmospheric pressure. (the density of sea water =1.03xx10^(3)xx10^(3)kgm^(-3),g=10ms^(-2))
Answer» Solution :Depth in sea water H = 1000 m Density of sea water `rho=1.03xx10^(3)xx10^(3)kgm^(-3)` Acceleration of gravity `g=10ms^(-2)` ATMOSPHERIC pressure at sea water SURFACE, `P_(a)=1.01xx10^(5)Nm^(-2)` (a) Absolute pressure at h depth, `P=P_(a)+hrhog` `=1.01xx10^(5)+1000xx1.03xx10^(3)xx10` `1.01xx10^(5)+103xx10^(5)` `=104.01xx10^(5)Pa` `=104atm[because10^(5)Pa=1atm]` (b)GAUGE pressure `P-P_(a)=hrhog=P_(g)` `therefore P-P_(a)=1000xx1.03xx10^(3)xx10` `P_(g)=103xx10^(5)Pa` where gauge pressure `P_(g)=P-P_(a)` `=103 atm` The pressure outside the submarine is `P=P_(a)+hrhog` and the pressure inside it is `P_(a)` Therefore The NET pressure acting on the window is gauge pressure `P_(g)=rhogh` The area of the windown `A=20cmxx20cm` `=400cm^(2)` `=400xx10^(-4)m^(2)` `therefore` The force acting on Windown, `F=P_(g)A` `=103xx10^(5)xx400xx10^(-4)` `=41200xx10` `thereforeF=4.12xx10^(5)N`