we have a cylinder with a SA of 250 square centimetres. the height is twice as big as the radius. what is the height of the cylinder?
Thanks so much!!!
how to find radicand height given surface area cylinder?
2016-10-18 8:01 pm
回答 (3)
2016-10-18 10:38 pm
250 = 2 π r ² + 2 π r h
250 = 2 π r ² + 4 π r ²
250 = 6 π r ²
r = [ 250 / 6π ]^(1/2)
h = 2 [ 250 / 6π ]^(1/2)
h = 22.9 cm
250 = 2 π r ² + 4 π r ²
250 = 6 π r ²
r = [ 250 / 6π ]^(1/2)
h = 2 [ 250 / 6π ]^(1/2)
h = 22.9 cm
2016-10-18 8:23 pm
Assuming cylinder is closed at both ends
SA = 2πr^2 + 2πrh
h = 2r
SA = 2πr^2 + 2πr(2r)
= 6πr^2
Therefore
6πr^2 = 250
r = √(250/6π
height, h = 2√(250/6π
= 7.283656204
= 7.28 cm
SA = 2πr^2 + 2πrh
h = 2r
SA = 2πr^2 + 2πr(2r)
= 6πr^2
Therefore
6πr^2 = 250
r = √(250/6π
height, h = 2√(250/6π
= 7.283656204
= 7.28 cm
2016-10-18 8:13 pm
h = 2r
lateral area = 2πrh = 2πr(2r) = 4πr² cm²
base area = top area = πr² cm²
total surface area = 4πr² + 2(πr²) = 6πr²
6πr² = 250
r² = 250/(6π)
r = √(250/(6π)) = 5√(5/(3π))
h = 2r
= 2·5√(5/(3π))
= 10√(5/(3π)) cm
lateral area = 2πrh = 2πr(2r) = 4πr² cm²
base area = top area = πr² cm²
total surface area = 4πr² + 2(πr²) = 6πr²
6πr² = 250
r² = 250/(6π)
r = √(250/(6π)) = 5√(5/(3π))
h = 2r
= 2·5√(5/(3π))
= 10√(5/(3π)) cm
收錄日期: 2021-04-21 23:42:51
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