Length and volume measurement – ruler and graduated cylinder
Integrated ScienceScientific Skills & MeasurementAges 11–12Virtual lab
Use it with your class: students open it from a link or a QR code, with no account needed.
Next in Scientific Skills & Measurement
Students drag an object along a ruler so one end lines up with the 0 mark, read its length to the ruler's resolution, and see the resulting reading error. They then drop the object into a graduated cylinder: the water level rises, and reading V₁ and V₂ gives the object's volume, V = V₂ − V₁. Changing the resolution of the ruler and cylinder shows how the recorded result depends on the instrument used.
Lesson: Measuring length and volume of liquids and non-absorbent solids; instrument range and resolution
What it shows
Every measuring instrument has a range, the largest value it can measure, and a resolution, the smallest division on its scale. A reading can only be recorded to the nearest division, so its uncertainty is up to half the resolution. This simulation applies these ideas to a 15 cm ruler and a 100 mL graduated cylinder. Length comes from the readings at both ends of the object, and the volume of an irregular solid that does not absorb water is found by displacement, V = V₂ − V₁, where 1 mL = 1 cm³.
How to use
Choose an Object to measure, drag it along the ruler until one end sits on the 0 mark, and read the other end. Change the Ruler resolution from 1 mm to 1 cm and compare the recorded lengths. Then press Drop into cylinder, read V₂ at eye level and subtract V₁. Switch on Show true value and error to check each result, and press Remove object to repeat with another Cylinder resolution.
Parameters you can change
- Object to measure Small stone, Eraser, Key, Iron bar
- Ruler resolution 1 mm (0.1 cm), 0.5 cm, 1 cm
- Cylinder resolution 1 mL, 2 mL, 5 mL
- Initial water in cylinder V₁ 30–80 mL
- Show true value and error
Questions to explore
- Why should one end of the object be placed exactly on the 0 mark of the ruler?
- With a cylinder resolution of 5 mL, by how much might a measured volume differ from the true volume?
- For which kinds of objects would the V₂ − V₁ displacement method give a wrong volume?
