A circular pool has a diameter of 12 feet. About how much water is needed to fill the pool to a depth of 4 feet?
a. 75 cubic feet
b. 150 cubic feet
c. 450 cubic feet
d. 1,800 cubic feet
2006-09-26 08:48:00 · 7 answers · asked by JoAnna 2 in Science & Mathematics ➔ Mathematics
Surface area = pi*r^2
Volume = 4*pi*r^2 = 4*36*pi
Since pi = approxe 3.14
the answer has to be c
2006-09-26 08:49:59 · answer #1 · answered by ? 7 · 0⤊ 1⤋
Forget about pi. Suppose the pool was square instead. Its volume would be 12*12*4 = 576 cubic feet.
Now how much smaller than a square pool do you think a round pool the same distance across might be?
a. about one-eighth
b. about a quarter.
c. about three-quarters.
d. three times bigger.
This way of thinking about it makes c. look a pretty safe bet to me.
2006-09-26 17:02:53 · answer #2 · answered by bh8153 7 · 0⤊ 0⤋
C. 4*pi*r^2 = 4*3.1416*6^2 = 452
2006-09-26 15:49:46 · answer #3 · answered by Will 6 · 0⤊ 0⤋
c. 452.3893344 cubic feet = 3,384.10722875 gallons
2006-09-26 15:57:16 · answer #4 · answered by Anonymous · 0⤊ 0⤋
V = pi*(r^2)*h=pi((d/2)^2)*h (d==2r)
Plug in values:
V=pi*(6^2)*4
Crank it out and choose the closest answer.
2006-09-26 15:53:49 · answer #5 · answered by Helmut 7 · 0⤊ 0⤋
C.
V=pie(r)(r)(height)
2006-09-26 15:51:30 · answer #6 · answered by Anonymous · 0⤊ 0⤋
C
2006-09-26 15:50:19 · answer #7 · answered by Demiurge42 7 · 0⤊ 0⤋