Question

the difference between outside and inside curved surface areas of the cylindrical metallic pipe 14 cm long is 352 cm sq. if the pipe is made of 3520 cm of metal, find the outer and inner radii of the pipe
plz solve it.......

Answer 1

The difference between the inner and outer surface is the height and hence the value of height is 14cm.
The CSA of cylinder is 2πrh

CSA of cylindrical pipe = 352 cm sq
2πRh - 2πrh
= 352 cm sq
2π(R-r)h
= 352 2x3.14x(R-r)x14 = 352 87.92 x (R-r)
= 352 (R-r) = 4.003
The volume of the pipe
= 3520 cu.cm πhR2 - πhr2)
= 3520 πh(R2 - r2)
= 3520 3.14x14x(R2 - r2)
= 3520 43.96 x (R2 - r2)
= 3520 R2 - r2 = 3520 / 43.96 = 80.07