- A metre rule (ruler) is used to measure length for distances between 1 mm and 1 meter.
- The SI unit for length is the meter (m).
- Precaution to be taken when using metre rule
- Make sure that the object is in contact with the ruler.
- Avoid parallax error.
- Avoid zero error and end error.
- To find the volume of a regular object, you can use a mathematical formula, you just need to make a couple of length measurements.
- To measure the volume of an irregular object you have to put the object into measuring cylinder with water. When you add the object it displaces the water, making the water level rise. Measure this rise. This is the volume of your object.
- For even smaller lengths, use a micrometre screw gauge.