|
9.3 Force
of gravity
i Words to know:
|
|
English term
|
Write the words again
|
Chinese term
|
|
1
|
Force of
gravity
|
|
重力/引力
|
|
2
|
Pull / Pulling
|
|
拉
|
|
3
|
Exert (... on…)
|
|
施加 (…於…)
|
|
4
|
Centre
|
|
中心
|
|
5
|
Celestial
bodies
|
|
天體
|
|
6
|
Weight
|
|
重量
|
|
7
|
Mass
|
|
質量
|
|
8
|
Matter
|
|
物質
|
i Fill in the blanks:
1 The Earth exerts a pulling force on every object on
or around it.
The force of gravity pulls
objects towards the centre of
the Earth
2 Other celestial bodies
also exert a force of gravity on objects on or around them.
3 The weight of an object on the
Earth is the force of gravity exerted by the Earth on the object.
It can be different
when it is measured on different celestial bodies.
4 The mass of an object is the
amount of matters
it contains.
It is the same in all places.
5 The unit of weight is newton
while that of mass is kilograms or grams (g).
6 An astronaut is weighing a
2kg block on planet X and the reading is 10N. The mass of the block on planet X
is 2kg and the mass of the block
on the Earth is 2kg . The force of gravity exerted by
planet X is on the block
is 10N.
The force of gravity of planet X is smaller (larger / smaller)
than that of the Earth.
The weight of the astronaut on planet X is smaller than his weight on the Earth
i Skill development – Writing
1.
The Earth exerts a force of gravity on every
object on or around it. The force pulls the objects
towards
the centre
of the Earth.
2. The Moon exerts a force of
gravity on every object on or around it. The force
pulls the objects towards the centre of the Moon.
3. Mars (火星) exerts a force of
gravity on every object on or around it.
The force pulls the
objects towards the centre of the Mars.
沒有留言:
張貼留言