5. Mass is the amount of matter in an object.
Mass and inertia: You can measure the mass of an
object by seeing how much force is required to
change its state of motion.
A 10kg object double inertia than
5kg object:
For same movement in both objects,
we must apply a double force in the
first one.
Mass indicates the inertia of a body.
6. Mass and gravity:
The gravitational field
of matter is another
measurement of
mass.
Jupiter’s mass =
310xEarth’s one.
If an object was set
right between them,
it would be attracted
to Jupiter by a 310
times higher force.
Finally, there is an equivalence of mass and energy.
You will study this later.
7. A body can have little
mass and big size
or a considerable mass
and a small size
Do bigger objects have more mass?
8. This is due to a body’s matter can be more or less
compacted, thus occupy more or less space.
You have already studied relation between mass of
a body and its size (its volume) is determined by
DENSITY.
9. No, mass and weight are not the same. It is
important to not confuse both concepts.
Are mass and weight the same?
mass is a measurement of how much matter
is in an object;
weight is a measurement of how hard gravity
is pulling on that object.
10. Your mass is the same wherever you are (on Earth,
on the moon, floating in space) because
the amount of stuff you're made of doesn't
change!!!!
What you call weight, is in fact your MASS!!!
Measured in kg in the IS.
11. How can I calculate my weight?
Your weight depends on how much gravity
is acting on you at the moment;
Earth’s gravity is 9’8m/s2, so…
weight = mass x gravity;
unit Newtons “N”
you would weigh less on the moon than on
Earth, and in interstellar space you'd weigh
almost nothing at all.
12.
13. What is your mass on Earth and on the Moon?
And your weight?
Data:
Earth’s gravity: 9’8 m/s2
Moon’s gravity: 1’61 m/s2
14. A material system is anykind of matter whose
limits are undefined. Ex: Clouds.
A body is anykind of matter whose limits are
defined. Ex: A ball.
15. Natural science studies from tiny things
(bacteria) to huge things (stars).
Scientist use two scales:
◦ A macroscopic scale: to measure things that can be
perceived using our senses.
◦ A microscopic scale: to measure things like cells or
atoms.
16. It’s a way of writing numbers to avoid writing
too many zeros.
It consists of writing using powers of ten.
Ex:
100.000.000.000.000.000.000.000.000=
1026
0’000000000000001= 10-15
17. 1. What is matter? What are the characteristics of
matter?
2.What is the difference between a material
system and a body?
3. Give an example of inertia in everyday life.
4. Calculate the weight of my dog on the Earth
and on the Moon, knowing it is 20kg. What is
its mass?
18. 6. In your notebook fill in the blanks using the
words of this unit.
Matter is everything that has……., ……… and is
the cause of ………. attraction.
7. Classify the following as bodies or material
systems:
a)A ball b) A galaxy c) The water in a river
d) The air in the atmosphere