Question

a metal pipes is 77cm long the inner diameter of a cross section in 4cm outer diameter being 4.4cm find inner csa , outer csa, volume

Answer 1

Length of pipe = 77 c.m.

Inner diameter = 4 c.m.

Outer diameter = 4.4c.m.

1) Inner curved surface area

radius = inner diameter / 2 => 4 c.m./2 => 2 c.m.

curved surface area = 2 / rh => 2* 22 * 77 => 2 *22* 11 = 968 c.m.2

_____________



2). Outer curved surface area

radius = outer diameter / 2 => 4.4 c.m. / 2 => 2.2 c.m.

curved surface area = 2 / rh

= 2 * 22* 2.2* 77

__________________ => 1064.8 c.m.2



3) total surface area

Let outer radius be R and inner radius be r

surface area on the end = 2 / ( R+r )( R -r )

= 2 *22 * ( 2.2 + 2) ( 2.2 -2)

_

7

= 2* 22* 4.2 * 0.2

________________ = 5.28 c.m.2

7

total surface area = 968 c.m.2 + 1064.8 c.m.2 +5.28 c.m.2 = 2038.08 c.m. 2