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4.1 Object mass
Why is it easier to All objects in nature, large and small – the Sun, the Earth, a human
move an apple than a being, a water droplet, a grain of sand – have an intrinsic property
watermelon? Why is called mass. Simply put, mass can be said to be a measurement of
it sometimes difficult the amount of matter that makes up a particular object. As you have
textbooks nis edu kz
learnt in Chemistry, objects (physical bodies) are made up of lots of
to make objects move
atoms and other smaller particles.
and even harder to
stop them moving? Mass is denoted by the letter m. The SI unit of mass is the kilogram (kg).
An object’s mass can be measured using many different types of
scales. Measuring an object’s mass means comparing it with the mass
of weights.
INV Measure the masses of at least 5 different objects in your classroom
using at least 3 different scientific devices. Include the scale division
of the scientific instrument and include the uncertainty in your
measurement. Compare the results you obtained for the same object
with different scales.
Supermarket scales
DID YOU KNOW?
The international standard
of the kilogram is made up
of an alloy of two metals:
platinum and iridium. It is
kept in Sèvres (near Paris).
More than 40 precise copies
Digital bathroom scales
of the international standard
kilogram have been sent
to different countries.
Kazakhstan owns one of
these copies. In practice,
other units of mass are used
as well: a tonne (t), gram (g),
milligram (mg).
Old-fashioned kitchen scales
1 tonne = 1000 kg (10 kg) 1 g = 0.001 kg (10 kg)
3
-3
3
-3
1 kg = 1000 g (10 g) 1 mg = 0.001 g (10 g)
-6
6
1 kg = 1 000 000 mg (10 mg) 1 mg = 0.000001 kg (10 kg)
Digital scales in a chemistry lab
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