I have a clyndrical water tank with a diameter of 32 feet and is 36 feet high. Can somebody please tell me how many sq. ft of surface area this thing has? Or even just the formulas I need to do it. I can't remember how to find the sq. ft. of a circle for the top and bottom and I can't remember how to figure out the circumference from the diameter. Thanks a lot
2006-09-25 05:18:17 · 7 answers · asked by eastern_mountain_outdoors 4 in Education & Reference ➔ Higher Education (University +)
Well, the radius is half the diameter. Therefore the radius(R) is 16 feet. The circumference of the base of the cylinder is 2*pi*R. Therefore the circumference is 2*3.14*16 = 32*3.14 = 10.48 feet. Now if you have a good imagination try to imagine cutting the cylinder on one side from top to bottom, and spreading out the cylinder on a flat surface. You will get a rectangle, and the area of the rectangle is base times height. The base, we just calculated is 100.48 feet, and the height is given:36 feet. Therefore the surface area of the side of the cylinder is 100.48 feet * 36 feet = 3617.28 sq. feet. This is probably the answer you are looking for. If you need to add the top and the bottom of the cylinder, then it is 2(one for bottom one for top) * the area of the circle. => 2*pi*R^2 => 2 * 3.14 * 16^2 = 1607.68 sq feet. Add this to the surface area of the side of the cylinder and you get 5224.96. Hope I was helpful. Good luck.
2006-09-25 05:29:31 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The area of the circle at the top and the bottom will be found by the formula: area = pi*radius squared
Remember that the radius is half of the diameter.
To find the middle rectangle, you need to find the circumference of the circle, circumference = pi*diameter.
Then once you have the circumference of the circle multiply by the height of your water tank.
I'm not sure what you need to use for pi, but the common number is pi= 3.14
Add all of the answers you got for the circles and rectangular surfaces.
Hope this makes sense. Good Luck.
2006-09-25 12:30:52 · answer #2 · answered by SmileyGirl 4 · 0⤊ 0⤋
For top and bottom. Their area is 'Pi' times the 'radius squared'. Pi(16^2). There are two of these (top/bottom)
For side, it might help if you imagined the side rolled out flat. That would be the circumference of the tank in length [Pi times diameter] Pi time 32 or 32Pi. That would be multiplied by the height of the tank or 36 so the answer is 36(32Pi).
2006-09-25 12:34:01 · answer #3 · answered by SPLATT 7 · 0⤊ 0⤋
Circumference = Pi x Diameter
3.14 x 32 = 100.48 ft. = circumference
Area of side = diameter x Pi x height
32 x 3.14 x 36 = 3617.28 sq. ft.
Area of top = Pi x radius squared
3.14 x 16 x 16 = 803.84 sq. ft.
Surface area of tank = 4221.12 sq. ft
(Sides + 1 End (top) = 4221.12 sq. ft.
If 2 ends, add 803.84 sq. ft.
2006-09-25 12:56:19 · answer #4 · answered by dathinman8 5 · 0⤊ 0⤋
If you're looking for just the surface area of the water at the top, it's pi x (radius squared).
If you're looking for the surface area of both the top and bottom combined, it's double that number.
If you want the surface area of the entire cylinder, including the sides, it's the previous number plus (diameter x pi x height).
2006-09-25 12:34:51 · answer #5 · answered by rainfingers 4 · 0⤊ 0⤋
tell me about it. thirty three and back in school here.
circumfrence. pi times diameter.
area pi times radius squared. pi being 3.1415...or 3.14 depending how technical you need to be.
almost forgot.
when you do the surface of the cylinder remember that the circumfrence needs to be multiplied by the height.
so the formulas you need are
pi times the square of the radius-remember to multiply that times two for the top and the bottom of the cylinder and add the total to the wall surface which will be pi times the diameter times the height. got it. hope it helps.
2006-09-25 12:22:53 · answer #6 · answered by SST 6 · 0⤊ 0⤋
http://www.math.com/tables/geometry/surfareas.htm
2 pi r^2 + 2 pi r h
2006-09-25 12:27:53 · answer #7 · answered by Manny 6 · 0⤊ 0⤋