Measurement: The Metric System, Tools and Practice

Volume

• The standard unit for measuring volume is the liter (l).
• Volume is the amount of space an object takes up.
• The tool used to measure length is the graduated cylinder.
• Other methods are also used, but we will not deal with them here.

More About Volume

• To measure the volume of liquids
  • use a graduated cylinder
  • express your measurement in liters (using prefixes discussed in the last lesson to express large or small quantities), or milliliters

• To measure the volume of an irregularly shaped object (like a rock)
  • use a graduated cylinder (suspend the object being measured from a string in liquid and calculate the change in height of the liquid in the graduated cylinder)
  • express your measurement in the unit cubic centimeter - cm³

• To measure the volume of a regularly shaped object (like a brick)
  • multiply the length of the object by the width by the height (l x w x h)
  • express your measurement in the unit cubic centimeter - cm³

How to read the graduated cylinder:

• Here is a graduated cylinder. (A picture of a tall, graduated glass cylinder which has volume measurements drawn on its side. It is used to measure the volume of liquids.)
• It is a cylinder with graduated marks on it.
• This means that the marks start at zero at the bottom of the cylinder with the measures getting larger as they go up.
• Graduated cylinders come in various sizes for measuring different sized amounts.
• The one pictured here is a 100ml graduated cylinder.

Measuring Volume: Examples

Volume

• Let's start with the volume of a regular shaped object like a rectangular solid
  • measure the sides and calculate the volume by taking the length multiplied by the width multiplied the height.
  • Example: 3 cm x 4 cm x 5cm = 60 cm³

(A picture of a rectangular box which is 5 cm wide, 4 cm tall and 3 cm deep.)

Find the volume of the following regular solids:

A cube with all sides equal to 10 cm = __________________

A rectangular solid with sides equal to 2 cm, 8 cm, and 10 cm = ___________________

Check Your Answers

Measuring Volume: Examples

(A picture of four drawings of graduated cylinders containing liquid. Each graduated cylinder has milliliter gradations and each cylinder has a different level of liquid in it. The volume of the liquid is measured by reading the lowest point of the curve of the liquid, called the meniscus. The volumes of the four cylinders from left to right are: 24 milliliters, 39 milliliters, 40.5 milliliters and 54 milliliters.)

• When reading a graduated cylinder, always read from the bottom of the curve of the liquid. This curve is called the meniscus.
• *Note:
  • The graduated cylinders shown in a and d have increments of 2 marked between the milliliter lines.
  • The graduated cylinders shown in b and c have increments of 2 marked between the milliliter lines.

Measuring Volume

(Graduated Cylinder Photo on the Left: A picture of a clear glass graduated cylinder with clear liquid in it. The top of the liquid sits at the 84 mark and the meniscus of the liquid sits at the 83 mark. Graduated Cylinder Photo on the Right: A picture of a clear glass graduated cylinder with clear liquid in it. The top of the liquid sits at the 55 mark and the meniscus of the liquid sits at the 53 mark.)

What is the volume of the liquid being measured?

Left Image: __________________

Right Image: _________________

Check Your Answers

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