1) the curved surface area of a cylinder is 320cm^2 and its height is 6cm. Find its
(a) base radius, (b)volumn.
(give ur answers in terms of π.)
(show steps)
2)there are 2 cylinders of the same volumn. the first cylinder has a height of 20 cm and a base radius of 2cm; the second cylinder has a height of 5cm. Find the base radius of the second cylinder. (show steps)
form 2 maths.
2007-05-07 7:15 am
回答 (2)
2007-05-07 7:32 am
✔ 最佳答案
1.(a.)Let the base radius be xcm,
2πx * 6 = 320
12πx = 320
x = 80/3π
so the base radius is 80/3π cm
(b)
volume = π(80/3π)^2 * 6
= 12800/3π cm^3
2.
let the base radius of the second cylinder be ycm
π(2)^2 * 20 = π(y)^2 * 5
80π = 5πy^2
y^2 = 16
y = 4
so the base radius of the second cylinder is 4cm
2007-05-07 7:38 am
a.Curved surface area= 2π r x height ( r = radius of base)
2πr x 6 = 320
r =8.49 cm
b. Volumn= base area * height
= r^2π * 6
= (8.49)^2 x 6 x π
= 1358cm^2
2. Let the base area of second cylinder be R
(2)^2 x π x 20 = R^2 x π x 5
R=4cm
2πr x 6 = 320
r =8.49 cm
b. Volumn= base area * height
= r^2π * 6
= (8.49)^2 x 6 x π
= 1358cm^2
2. Let the base area of second cylinder be R
(2)^2 x π x 20 = R^2 x π x 5
R=4cm
收錄日期: 2021-05-03 02:10:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070506000051KK06030