Question

a metal pipe is 154cm long the inner diameter of a cross section is 8cm the outer diameter being 8.8cm find its total surface area​

Answer 1

Answer:

Length =77cm,  

Inner diameter =4cm, hence inner radius (r)=2cm

outer daimeter =4.4cm, hence outer radius (R) =2.2cm

Height of the pipe =length

⇒Inner surface area ( inner CSA) = 2πrh

⇒ Inner CSA = 2×722×2×77

⇒Inner CSA = 968cm2

Outer CSA= 2πRh

⇒Outer CSA = 2×722×2.2×77

⇒Outer CSA= 1064.8cm2  

Now the total surface area on the ends = 2π(R−r)(R+r)

⇒2×722×4.2×0.2

⇒5.28 cm

The total surface area=outer CSA + Inner CSA + TSA on the ends  

The total surface area = 1068.8+968+5.28

The toal surface area = 2038.08 cm2

Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation: