Answer:
The mass of the pipe is [tex]465\ g[/tex]
Step-by-step explanation:
step 1
Find the volume of the steel pipe
The volume is equal to the area of outside circle minus the area of inside circle, multiplied by the length of the pipe
so
[tex]V=\pi [r2^{2}-r1^{2}]L[/tex]
we have
[tex]r2=2/2=1\ cm[/tex] ---> the radius is half the diameter
[tex]r1=1.8/2=0.9\ cm[/tex] ---> the radius is half the diameter
[tex]L=100\ cm[/tex]
[tex]\pi=3.14[/tex]
substitute
[tex]V=(3.14)[1^{2}-0.9^{2}](100)=59.66\ cm^{3}[/tex]
step 2
Find the mass
The mass is equal to the density multiplied by the volume
so
[tex]m=7.8(59.66)=465\ g[/tex]
