Problema Solution
A section of concrete pipe 30 m long has an inside diameter of
1.2 m and an outside diameter of 1.8 m. What is the volume of
concrete in this section of pipe?
Answer provided by our tutors
The volume of the concrete V equals the difference of the volume of the cylinder with diameter of 1.8 m and height of 3.0 m and a cylinder with diameter of 1.2 m and height 3.9 m:
V = (1.8/2)^2 pi * 3.0 - (1.2/2)^2 pi * 3.0
V = 3 pi ((1.8/2)^2 - (1.2/2)^2)
V = 3 pi (0.9^2 - 0.6^2)
V = 3*3.14*(0.81 - 0.36)
V = 4.239 m^3
The volume of concrete in the pipe is 4.239 m^3.