Simple Static Pressure problem, with units

AI Thread Summary
To solve the static pressure problem for a bathtub with water at a depth of 20 inches, the relevant equation is P = pgh, where P is pressure, p is density, g is acceleration due to gravity, and h is height. The user attempted to calculate gauge pressure using a density of 1.94 slug/ft³ and converted 20 inches to 1.67 feet, but struggled with unit conversion to psi. It was suggested to use the standard density of water, approximately 62.4 pounds per cubic foot, to simplify the calculation. Understanding the definition of a pound and its relation to pressure units is crucial for accurate conversion. Proper unit handling will yield the correct pressure in both psia and psig.
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Homework Statement


Hi I'm having trouble solving this physics problem if anyone can help it would be greatly appreciated !

Static pressure problem: A bathtub contains water to a depth of 20 inches. Determine the pressure at the bottom of the bathtub in both [psia] and [psig] (a being absolute pressure and g being gauge pressure)


Homework Equations


im using P=pgh

The Attempt at a Solution


what I've tried doing was to find gauge pressure first: P=pgh=(1.94slug/ft^3)(32.2ft/s^2)(1.67ft). I got the 1.67 feet from converting 20 inches to feet. the answer i get is 104.11slug/s^2 but they want it in psi or lb/in^2 and i am having trouble converting these units =[
 
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Why don't you just convert the initial 20 inches to meters then solve for the standard SI units?
 
Well the problem is that i don't know how to get rid of the /s^2 in my final answer and even if i use the standard SI units ill still come up with an answer that has /s^2
 
That's the acceleration…s^2 is an SI unit.
 
Also…

look at the definition of what a pound actually is (in terms of units). That should fix things.
 
Instead of using different unit systems, 1 cu. ft. of fresh water weighs about 62.4 pounds. Knowing that number, you should be able to find psi given the depth of water in the bath tub.
 
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