Question

an iron pipe 20 cm long has an external diameter equal to 8cm.Thickness of the total surface area of the pipe​

Answer 1

Answer:

The pipe is 20cm long (l)

extension diameter is 25cm, thickness is 10m.

∴ exterior radius (R)= 225cm

interior radius (r)= 225−1= 223cm

So, the total surface area is

= exterior surface of the pipe +

interior surface of the pipe +

two ends of the pipe (thickness area)

=2π(R).l+2π(r).l+2(πr 2−πr 2 )=2π[l(R+r)+(R+r)(R−r)]

=2π(R+r)(l+R−r)

=2× 722 ×( 225+ 223 )(20+ 225− 223 )= 744×24×24=44×72

=3168

So, the total surface face area is 3168 sq.cm.