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Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

Cylinders!!! Volume, and Surface Area?

What are the Surface Area and Volume of these two cylinders?

1) Radius=7cm

Height=10cm

Surface Area=?

Volume=?

2) Diameter=10cm

Height=25cm

Surface Area=?

Volume=?

Help!!!

5 Answers

Relevance
  • looikk
    Lv 4
    1 decade ago
    Favorite Answer

    For cylinder,

    volume, v = pi x r x r x h

    surface area, s =( 2 x pi x r x h ) + 2(pi x r x r)

    where r = radius, h = height

    the last term for surface area 2(pi x r x r) are for the top and bottom covers if there is.

    1) Radius=7cm

    Height=10cm

    Surface Area =( 2 x pi x r x h ) + 2(pi x r x r)

    = (2 x pi x 7 x 10) + 2(pi x 7 x 7)

    = 140pi + 98pi

    = 238pi

    = 747.7 cm^2

    Volume=pi x r x r x h

    = pi x 7 x 7 10

    = 490pi

    = 1539.38 cm^3

    2) Diameter=10cm

    Height=25cm

    Hence, radius = 10/2 = 5cm

    Surface Area =( 2 x pi x r x h ) + 2(pi x r x r)

    = (2 x pi x 5 x 25) + 2(pi x 5 x 5)

    = 250pi + 50pi

    = 300pi

    = 942.5 cm^2

    Volume=pi x r x r x h

    = pi x 5 x 5 x 25

    = 1963 cm^3

  • 1 decade ago

    First of the formula findind the surface area of a cylinder is 2 area of the circles + the circumference( height). then the formula of the volume is pi r^2(height)

    1)SURFACE AREA

    2(pi 7^2) + 2pi(7) times 10

    98pi+ 140pi=238pi

    S= 238picm^2

    VOLUME

    pi7^2 times 10=490pi

    V=490picm^3

    2)SUFACE AREA

    2(pi5^2) + 2pi(5) times 25

    50pi+250pi=300pi

    S=300picm^2

    Volume

    pi5^2 times 25=625pi

    V=625picm^3

  • 1 decade ago

    The volume of a cylinder is H * pi * r^2.

    The surface area of the tube is 2 * pi * r * h (height * circumference).

    If they want you to include the top and bottom, add in 2 * pi * r^2

  • DanE
    Lv 7
    1 decade ago

    Volume = π • r² • height = ¼ • π • d² • height

    v = 3.14 * (7^2) * 10 = 1538.6

    (1 / 4) * 3.14 * (10^2) * 25 = 1962.5

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  • 1 decade ago

    I think

    1

    surface area=(22/7)*(1/2)*20+(22/7)*14

    Volume=(1/3)*((22/7)*7*7)*10

    use the same think on the other one

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