要有詳細的公式及列式
1. A wire,32cm long, is bent into the shape of quadrant.Find the area enclosed by the wire.
2. A water pipe of internal diameter 2.6cm delivers water at rate of 0.8m/s.How much water comes out per second?
3. Given two right cylindrical vessels A &B.The base diameters of vessels A & B are 4cm and 12cm respectively.Initially,A contains water to a depth of 18cm and B is empty.Thewaterin A is then pouredd into B.Find
a) the water level in B
b) The wetted surface area of B
暑期作業(Maths)
2007-08-22 6:49 pm
回答 (2)
2007-08-22 10:00 pm
✔ 最佳答案
1. The perimeter of the quadrant is 32cmLet r cm be the radius of the quadrant
1/4 (2* pi * r) = 32
r = 20.36 cm
Area of the quadrant = 1/4 ( pi * r^2)
= 1/4 ( pi * 20.36^2)
= 325.70 cm^2
2. The cross sectional area of the pipe = pi * (2.6/2)^2
= 5.31 cm^2
Hence, volume of water comes out per second = 5.31 * 0.8 * 100
= 424.8 cm^3
3. (a)Volume of water in vessel A = pi * r^2 *h
= pi * (4/2)^2 * 18
= pi * 72 cm^3
Let h cm be the water level in vessel B
pi * (12/2)^2 * h = 72 * pi
h = 2
Water level in vessel B is 2cm
(b) Wetted surface area = 12 * pi * 2 + pi * (12/2)^2
= 24*pi + 36*pi
= 188.57 cm^2
2007-08-22 10:13 pm
1. 32/4=8, 8 X 8 = 64
2. 2.6/2= 1.3 (22/7) X 1.3cm X 1.3cm X 80cm = 424.74 cm3
3. 2x2x (22/7) x18= 226.19cm3
226.19/ (6x6x(22/7))= 2cm
a. 2 cm
(6x6x (22/7))+(12 x (22/7) x2)=188.495....cm2
2. 2.6/2= 1.3 (22/7) X 1.3cm X 1.3cm X 80cm = 424.74 cm3
3. 2x2x (22/7) x18= 226.19cm3
226.19/ (6x6x(22/7))= 2cm
a. 2 cm
(6x6x (22/7))+(12 x (22/7) x2)=188.495....cm2
收錄日期: 2021-04-13 13:03:53
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