Learn how to measure length accurately using standard units, and understand what motion means.
Length is measured in standard units like metres and centimetres, using tools such as a ruler or measuring tape, to ensure everyone gets the same result.
Why can't we use a hand-span to measure length accurately for scientific purposes?
Because hand-spans differ from person to person, so the same object would give different measurements — a standard unit is needed for consistency
Convert 250 centimetres into metres.
250 cm = 2.5 m
Objects can move in different ways: in a straight line (rectilinear motion), along a circular path (circular motion), or back and forth (oscillatory motion).
What type of motion does a child on a swing show?
Oscillatory motion (back and forth)
What type of motion does a car moving on a straight road show?
Rectilinear (straight-line) motion
1. What is the standard unit of length?
2. Convert 5 metres into centimetres.
3. What type of motion does a fan blade show?
4. What type of motion does a pendulum show?
5. Why is a standard unit important in measurement?