Skip to main contentSkip to solution

A drainage tile is a cylindrical shell 21cm long. The inside and outside diameters are 4.5 cm and 5.1 cm, respectively.

What is the volume of clay required for making a tile?

Solution

✅ Correct Option: 1

The drainage tile is a cylindrical shell with:

  • Length = 21 cm
  • Outside diameter = 5.1 cm
  • Inside diameter = 4.5 cm

The outside radius R=5.12=2.55R = \dfrac{5.1}{2} = 2.55 cm

The inside radius r=4.52=2.25r = \dfrac{4.5}{2} = 2.25 cm


The volume of clay is the volume of the outer cylinder minus the volume of the inner cylinder.

Volume of clay =πR2h−πr2h= \pi R^2 h - \pi r^2 h

=πh(R2−r2)= \pi h (R^2 - r^2)


Calculate R2R^2:

R2=(2.55)2=6.5025R^2 = (2.55)^2 = 6.5025

Calculate r2r^2:

r2=(2.25)2=5.0625r^2 = (2.25)^2 = 5.0625


Find the difference:

R2−r2=6.5025−5.0625=1.44R^2 - r^2 = 6.5025 - 5.0625 = 1.44


Volume =π×21×1.44= \pi \times 21 \times 1.44

=30.24π= 30.24\pi cm³

Therefore, the volume of clay required is 30.24π30.24\pi cm³.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question