1.1 Physical quantities and measurement techniques IGCSE Physics

Ruler can only measure until 1 mm at the lowest.

​It means we need a device that more accurate and more precise than a ruler

​Can you guess the length of this block?

A Caliper can measure the length until 0.1 mm accurately,
Micrometer even can do better, until 0.01 mm accurately.

Accuracy

Precision

how close a measured value is to the actual (true) value.

how close the measured values are to each other.

​​1. Motion, force, and energy

​YES, by taking multiple measurements.
Think about this case. And find it yourself!

​To measure a thickness of one sheet of a paper, I make a multiple measurements by stacking the paper into 500 sheets.

Based on the picture beside, can you find the answer?

Measuring Volume → 3 dimension (x-axis, y-axis, and z-axis) → unit=meter^3

Measuring Length → 1 dimension (x-axis or y-axis) → unit=meter

Measuring Area → 2 dimension (x-axis and y-axis) → unit=meter^2

​If the shape is regular (cube, cuboid, cylinder, sphere etc), just use the formulae you learned from mathematics lesson🤪

​You can measure the volume by the displacement of the water in a beaker. see picture below!

​When measuring the volume of the liquid, we can use the apparatus from the lab called a beaker.

​The line on the beaker body represents the volume called graduation line.

When measuring liquid you will witness the water is curved on the tip. This curved called meniscus. For water you should measure the volume from the bottom of its meniscus.

​How you measure shorts interval of time?

The figure shows the typical lab pendulum.

If you pull the bob(the sphere) gently to one side and release it, the pendulum will swing from side to side.

The time for one oscillation of a pendulum (when it swing from left to right and back again)
is called its period.

​How you measure the period of the pendulum accurately?