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Martin, Engineer
Category: General
Satisfied Customers: 4776
Experience:  i'm 41 and i never stopped studying and experimenting
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I have a 500 gal L.P tank or propain tank and i want to turn

Resolved Question:

I have a 500 gal L.P tank or propain tank and i want to turn it into a submarine but i dont know how many gal of water it would take to sink it.this is key for wen it comes time to make the balist tanks .I dont know the weight of the tank either.(Not looking good )
Submitted: 6 years ago.
Category: General
Expert:  Martin replied 6 years ago.
HelloCustomer welcome to Just Answer.

What you want to know is what is the force that will bring equilibrium:

F(buoyant) = -pVg

p = density of the fluid

V = volume of the object being submerged

g = standard gravity on Earth

water (not salty) = 1000 kg m^3

V= 500 gal = 1.8927 m^3

g= 9.81 N/Kg

F = -1000*1.8927*9.81 = -18567.387 N of force up or simply 1892.70 Kg of water.

As you see you need to fill all the 500 gal of water with just water to get equilibrium if we suppose an infinitely thin tank. That solve nothing :) We need the volume of material of the tank and it's nature (probably steel). Also you will have to add material to this, because even if the real tank is more heavy that our ideal tank, you will need to add weight to the whole thing, inside or outside the submarine (a human body will not be enough.

Edited by Martin on 11/20/2009 at 3:42 AM EST
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