Thursday, January 7, 2010

What is the approximate weight of oil in a container 3 feet high and 9 inches in diameter?

What is the approximate weight of oil in a container 3 feet high and 9 inches in diameter? (Oil weighs approximately 55 pounds per cubic foot.)





45 pounds.


82 pounds.


53 pounds.


73 pounds.What is the approximate weight of oil in a container 3 feet high and 9 inches in diameter?
Area of bottom of container = 蟺r虏


Converting this to square feet, area will be:


A = 蟺( (9/2) / 12)虏 = 0.4418 square feet





Volume is area x height


V = (0.4418 sq ft)(3 ft) = 1.325 cubic feet





Weight = volume * density


W = (1.325 cu ft)( 55 lbs / cu ft) = 72.9 lbs





Your answer will thus be


73 poundsWhat is the approximate weight of oil in a container 3 feet high and 9 inches in diameter?
73 pounds, assuming the container is cylindrical from the reference to its diameter.





The diameter is 9 inches or .75 foot. Halve it (to get the radius), square that and multiply by PI, to get the area of the base in square feet. Multiply that by 3 to get cubic feet, then by 55 pounds to get the weight of the oil.



So you need to calculate the volume inside the oil container.


The formula is Volume is


V = (pi) h r^2


you have d = 9 inches so first convert it to feet


d = 9 in * (1 ft/12 in) = (9/12) ft = (3/4) ft


r = d/2 = (3/4)/2 ft = (3/8) ft


V = (pi) (3 ft) (3/8 ft)^2


V =(27(pi)/64) ft^3


Weight of the oil = V * 55 lb/ft^3


W = (27(pi) ft^3)/64 *55 lb/ft^3


W = ~ 72.85 lb



9 inches = 3/4 feet diameter, so 3/8 feet radius


Volume = pi * r^2 * h


V = pi * (3/8 ft)^2 * 3 ft


V = pi * 9/64 square feet * 3 ft


V = 27/64 * pi cubic feet


V = approx. 5.3 cubic feet.





55 pounds/cubic foot implies approx. 71.5





The closest of your possible answers is 73 pounds.
Weight = Volume * Density





where





Volume = (pi/4)(9/12)^2(3) = 1.325 ft^3





Density = 55 lbs/ft^3





and substituting values,





Weight = (1.325)(55) = 73 lbs. --- this is the fourth option in your choices.
http://en.wikipedia.org/wiki/Cylinder_(g鈥?/a>






EDIT: I calculated with diameter instead of radius. I'm an idiot.
pi(.375)^2*3=1.325


1.325*55=72.89





So 73 pounds

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