1.1 Physical quantities and measurement techniques IGCSE Physics

​1. Motion, force, and energy

​Making Measurement

​By Muhammad Arief Kurniawan
Mutiara Harapan Islamic School

Labelling

What things you have to consider when measuring length with a ruler?

Drag labels to their correct position on the image

read the other end of the wire

start point normally must at zero

The wire must be straight

​1. Motion, force, and energy

What if the measurement is ambiguous??

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?

​1. Motion, force, and energy

That's Why we have a vernier caliper and micrometer screw gauge

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

​Accuracy and Precision

Accuracy

Precision

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

how close the measured values are to each other.

aCcurate means Correct (bullseye).

pRecise means Repeating.

​How to remember?

​​1. Motion, force, and energy

Match

Match the following terms.

High Accuracy but Low Precision

Low Accuracy but High Precision

High Accuracy and High Precision

• High Accuracy but Low Precision

• Low Accuracy but High Precision

• High Accuracy and High Precision

​Measuring small length can be tricky, Is there a measurement technique we can learn?

​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 Volumes

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🤪

​but, What if the shape is irregular?

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

Details to be remembered!! (Because it is out in the exam)

​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.

Open Ended

The volume of a piece of wood which floats in water can be measured as shown in figure above.

a. Write a paragraph to describe the procedure.

b. state the volume of the wood.

Match

Measuring Time

digital timer

analogue timer

sand timer

• digital timer

• analogue timer

• sand timer

​Similar question, different situation.

​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?

Open Ended

Answer the question here...

Categorize

Options (6)

1.1.1 Describe the use of rulers and measuring cylinders to find a length or a volume

1.1.2 Describe how to measure a variety of time intervals using clocks and digital timers

I understood

I understoods

1.1.3A Determine an average value for a small distance by measuring multiple times

1.1.3B Determine an average value for a short interval of time by measuring multiples

Categorise these Learning Objectives (LO) based on your understanding. If you understood all the LO, choose "I understood" options in orange and red columns.

I understood

I confused

I don't understand