Question

A boat has a porthole window, of area 0.00849 m^2, 6.25 m below the surface. The density of sea water is 1027 kg/m^3. The air inside the boat is at 1 atm. What is the net force on the window?

Answer 1

Answer: 534.6 N

Step-by-step explanation:

This answer works for Acellus!

Answer 2

`325.65\ \text{N}` outward.

Step-by-step explanation:

`\rho` = Density of water =
`1027\ \text{kg/m}^3`

g = Acceleration due to gravity =
`9.81\ \text{m/s}^2`

h = Height of the water = 6.25 m

A = Area of the window =
`0.00849\ \text{m}^2`

`P_i` = Internal pressure of the boat =
`1\ \text{atm}=101325\ \text{Pa}`

Pressure by the water on the window

`P=\rho gh\\\Rightarrow P=1027* 9.81* 6.25\\\Rightarrow P=62967.9375\ \text{Pa}`

Net pressure on the window

`P_n=P-P_i=62967.9375-101325=-38357.0625\ \text{Pa}`

Force is given by

`F=P_nA\\\Rightarrow F=-38357.0625* 0.00849\\\Rightarrow F=-325.651460625\ \text{N}`

Net force on the window is
`325.65\ \text{N}` outward.