Key learning points

1. The vital capacity of the lungs is the maximum volume of air that can be exhaled after inhaling fully.
2. How to measure vital capacity using simple apparatus.
3. The closer a measurement is to the true value, the more accurate it is said to be.
4. An estimate is an approximate (rough) value of a quantity (without taking accurate measurements).
5. An estimate of lung volume can be calculated from a measurement of vital capacity.

Keywords

• Volume - The amount of three-dimensional space occupied by a substance; usually measured in cm³.

• Vital capacity - The maximum volume of air that can be breathed out after breathing in fully.

• Accurate - The closer a measurement is to the true value, the more accurate it is said to be.

• Meniscus - The surface of a liquid, which may appear curved.

• Estimate - An approximate (rough) value of a quantity (obtained without taking accurate measurements).

Common misconception