Tuesday

March 31, 2015

March 31, 2015

Posted by **COFFEE** on Tuesday, June 26, 2007 at 4:45pm.

Find the hydrostatic pressure on one end of a water trough full of water, the end of which is a trapezoid with given dimensions: top of trapezoid = 20 feet, sides of trapezoid both = 8 feet, bottom of trapezoid = 12 feet.

Depth of water = 8 feet

Density of water = 62.4 lb/ft^3

gravity = 32.15 ft/s^2

a/(8-xi*) = (4ft)/(8ft)

a = (8-xi*)/2 = 4 - (xi/2)

Wi = 2(6+a) = 2(6+4-(1/2)xi*)=20 - xi*

Ai = Wi*delta x = (20-xi*)delta x

Pi = rho*g*d

Pi = (62.4 lb/ft^3)(32.15 ft/s^2)xi

Fi = Pi*Ai

Fi = (62.4 b/ft^3)(32.1/s^2)xi*(20-xi*) delta x

Fi = Integral from 0 to 8 of:

(62.4)(32.15)x(20-x)dx

Fi = 2006.16*Integral 0 to 8 of: (20x-x^2)dx

=2006.16[10x^2-(x^3)/3] evaluated at 0 and 8

=9.42 x 10^5 (what are the units here? lb/(ft^3*s^2)???

Your density of water in lbs/ft^3 is the weight of water at sea level. It is not mass density. So no need to multiply by 32 ft/sec to turn into a force. That is one error.

I dont follow your work, I probably need a diagram to see what your x and dx is. But I know the area of the end is appx 16*6 or appx 100 ft squared (engineering estimate)and the average depth is about 3 ft, so the area*density water*depth is about E2*62*3 appx 18K lbs, which is about half of your adjusted answer (adjusted by dividing by 32). Recheck your calcs.

also, your depth is wrong. If the slanted sides are 8 ft, the depth is about six feet.

- Calculus - Hydrostatic Pressure -
**Josh**, Thursday, July 29, 2010 at 4:28pmHmm. . . Let me think about this one.

- Calculus - Hydrostatic Pressure -
**Anonymous**, Sunday, October 30, 2011 at 5:27pm16049.28

**Answer this Question**

**Related Questions**

College Physiology - At the venular end of the capillary, the hydrostatic ...

Calculus - A trough is 3 feet long and 1 foot high. The vertical cross-section ...

anatomy&physiology - What directions glomerular hydrostatic pressure,capsule ...

math - A water trough is 4 m long and its cross-section is an isosceles ...

calculus - A trough is 9 feet long and 1 foot high. The vertical cross-section ...

calculus - A trough is 10 feet long and 1 foot high. The vertical cross-section ...

Calculus Help Please!!! - A water trough is 5 m long and has a cross-section in ...

calculus - A water-trough is 10m long and has a cross-section which is the shape...

I NEED HELP PLEASE - A trough is 8 meters long, 3 meters wide, and 5 meters deep...

DUE AT MIDNIGHT PLEASE HELP- Calculus - A trough is 5 meters long, 1 meters wide...