Measurement of length, volume, weight, temperature, time in laboratory, secondary, year 7
23
MEASUREMENT Length Temperature Volume Time Weight Author : Mr Lam
description
measurement of time, length, volume, temperature and weight
Transcript of 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.
