Answer:
Length of pipe = 21 cm
Internal diameter = 4 cm
Internal radius = \frac{4}{2} = 2 cm24=2cm
Thickness = 0.5 cm
Outer radius = 2+0.5=2.5 cm
Volume of pipe =\pi R^2 h - \pi r^2 hπR2h−πr2h
Volume of pipe =\frac{22}{7} (2.5)^2 (21)-\frac{22}{7}(2)^2(21)=148.5 cm^3
=\frac{22}{7} (2.5)^2 (21)-\frac{22}{7}(2)^2(21)=148.5 cm^3722(2.5)2(21)−722(2)2(21)=148.5cm3
Hence The volume is 148.5 cubic cm.
#more
The thickness of a metal pipe is 1.5cm. The inner diameter is 21cm. What is the volume of metal required for a pipe of length 7cm
Answer: 
Step-by-step explanation:

Subtract 20x

add 15

Combine like terms

Divide by -25 (NOTE: When dividing or multiplying by negative numbers the inequality sign flips.)

Answer:
-7x^2 + 3x + 5
Step-by-step explanation:
-3x^2 + x + 5 - 4x^2 + 2x
If you convert 62 kilograms to lbs it will give you 136.687 lbs