The Volume of Cylinders

Concept sheet | Mathematics

The volume of a cylinder relates to the space it occupies in its environment. Even though the solid is not part of the prisms family, when calculating its volume, the same formula is used. The only difference is the area of a base will always be that of a circle.

Formula

​|V = A_b \times h|       or      |V=\pi r^2\times h|

where

||\begin{align} A_b &= \text{Area of a base}\\ h &= \text{height of the cylinder}\\ r &= \text{radius of the base}\end{align}||

Example

Health organizations set up vaccination programmes to protect people from various diseases. They use the following equipment to give people vaccines.

Cylinder-shaped syringe to determine volume

According to the example, what is the maximum volume of medicine, in |\text{mm}^3,| that this syringe can hold?

  1. Identify the solid
    From the illustration, we can determine it is a cylinder.

  2. Apply the formula

    ||\begin{align}V &= A_b \times h\\ \\ &= \pi r^2 \times h \\\\ &= \pi \left(\dfrac{6}{2} \right)^2 \times 90 \\\\ &= \pi(3)^2\times 90 \\\\ &\approx 2\ 544{.}69 \ \text{mm}^3\end{align}||

  3. Interpret the answer 
    From the given information, the syringe can contain a maximum amount of approximately |2\ 544{.}69 \ \text{mm}^3| of medication. 

    Note : the radius must be used – not the diameter.

Sometimes, the base measurement or the height of the cylinder must be found, but only the volume is given. This situation is called finding a missing measurement of a cylinder from the volume. In this case, the approach is a little different, but it is still necessary to remember the formula used for the volume of a cylinder.

Vidéo

The Volume of Prisms and Cylinders

The Volume of Prisms and Cylinders

Moments in the video:

  • 00:00-Definition of volume
  • 00:58-Volume formula
  • 01:40-Volume of a prism
  • 02:42-Volume of a cylinder

Exercises

Exercise

The Area and Volume of Cylinders (Secondary 3)

Mathematics Secondary3
Exercise

Area and Volume of a Cylinder – Word Problems (Secondary 3)

Mathematics Secondary3