Measurement of length, volume, weight, temperature, time in laboratory, secondary, year 7

MEASUREMENT

Length Temperature

Volume Time

Weight

Author : Mr Lam

Length

In laboratory, we use “meter-rule” or “half-meter rule” to measure length

1km = 1000m1 m = 100cm1cm = 10mm

How to meter-rule

Challenge 1:

How can you measure the diameter of pencil leads?

Challenge 2:

Critical thinking

Ancient Egyptians measuring unit is cubit. One cubit is the length from the fingertip to the elbow.

What are the advantages and disadvantages of the Egyptians measurement system?

If you are living in ancient Egypt, what would you suggest to improve the measurement system?

Volume

Volume is a measure of the space an object occupied.

Volume is measured by cubic meters For smaller volume, we use cubic

centermeters

For liquid, we use “Litre” (L) or “millilitre” (mL) as units to measure the volume

How to read a measuring cylinder

Measure volume of small irregular solid

Measure volume of large irregular solid

Challenge

How can you measure the volume of something that floats on water?

e.g. Styrofoam

Challenge 2

Is beaker a good instrument to measure volume? How can you find it out?

Weight/Mass

Mass is a measure of the amount of substances The bigger the mass, the more difficult to move

the object (inertia) The mass of an object always the same no matter

which part of the universe the object is. The unit of mass is kilogram (kg) or gram (g)

Weight is a measure of how much gravitational pull from the centre of the Earth.

Weight of an object on the Earth is different it is on the Moon.

The unit of the weight is Newton (N)

On the surface of the Earth.

In the daily life, one says his weight is 60kg. Stickily speaking, this is scientifically incorrect. He is better to say his weight is approximately 600N

Examples of scales/ balances

The most creative weighing scale?

Temperature

Temperature is a measure of how hot or cold of an object

The instrument used to measure temperature is called “thermometer”

The unit of temperature is degree Celius (C), or Kelvin (K)

Human average core body temperature is

Examples of thermometer

Time

Time is measured in second (s), minute (min) or Hour (hr)

We use watch or clock to measure time In laboratory, the standard instrument to

measure time is stop watch.