how many outlet pipes of diameter 1.5 cm are needed to carry the same amount of water as one pipe having a diameter of 3 cm?
2007-10-04 12:26:01 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Two, multiply 1.5 by two and you get 3 cm.
2007-10-04 12:29:11 · answer #1 · answered by Allen 1 · 0⤊ 0⤋
4
2007-10-04 19:31:40 · answer #2 · answered by Z W 2 · 0⤊ 0⤋
A pipe with diameter 1.5 has radius 0.75, area = PI r squared, so .75 x .75 x PI = 0.5625 PI
A pipe with diameter 3 has radius 1.5, area = 2.25 PI
Divide 2.25 PI/0.5625 PI, the PI cancels out, 2.25/0.5265 = 4.27+
You need the ratio of the areas, not just the diameters. Draw a picture with measured pipe cross-sections to see this.
2007-10-04 19:37:52 · answer #3 · answered by Howard H 7 · 0⤊ 0⤋
2
assuming that the pipes have the same slope and mannings roughness coefficient
2007-10-04 19:29:26 · answer #4 · answered by C 1 · 0⤊ 0⤋
x * 1.5 = 3
x = 2
2007-10-04 19:29:25 · answer #5 · answered by Anonymous · 0⤊ 0⤋
1.5x=3
/1.5 /1.5
x=2
2007-10-04 19:29:18 · answer #6 · answered by gravy 2 · 0⤊ 0⤋