Question

(a) Calculate the absolute pressure at the bottom of a fresh- water lake at a depth of 27.5 m. Assume the density of the water is 1.00 3 103 kg/m3 and the air above is at a pressure of 101.3 kPa. (b) What force is exerted by the water on the window of an underwater vehicle at this depth if the window is circular and has a diameter of 35.0 cm?

Answer 1

(a) The absolute pressure is 371.6 kPa

(b) The force exerted by the water is 26.0 kN

Explanation: Please see the attachments below

Answer 2

a)
`P = 370.993\,kPa`, b)
`F = 25.948\,kN`

Step-by-step explanation:

a) The absolute pressure at a depth of 27.5 meters is:

`P = P_(atm) + P_(man)`

`P = 101.3\,kPa + \left(1000\,(kg)/(m^(3))\right)\cdot \left(9.807\,(m)/(s^(2)) \right)\cdot (27.5\,m)\cdot \left((1\,kPa)/(1000\,Pa) \right)`

`P = 370.993\,kPa`

b) The force exerted by the water is:

`F = (P - P_(atm))\cdot A`

`F = (370.993\,kPa-101.3\,kPa)\cdot \left((\pi)/(4) \right)\cdot (0.35\,m)^(2)`

`F = 25.948\,kN`