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8/18/2019 Chapter 9 Stability
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FORM 2 SCIENCE
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ISI KANDUNGAN
(CONTENT)9.1 Kestabilan
(Stability)
9.2 Kepentingan Kestabilan
( Importance of Stability)
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9.1 KESTABILAN (STABILITY)
1. Suatu objek yang stabil ialah objek yang tidak
mudah tumbang apabila diberikan tolakan yang
sedikit.
( A stable object is an object that does nottopple easily when it is pushed slightly.)
2. Manakala objek yang tidak stabil ialah objek
yang mudah tumbang.
(On the other hand, an unstable object easily
topples over.) 3
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3. Kestabilan dipengaruhi oleh pusat graviti.
(Stability is influenced by centre of gravity ).
4. usat graviti sesuatu objek merupakan titik
keseimbangan ke atas objek.
(The centre of gravity of an object is a point of
equilibriu on the object.)
!. Suatu objek dikatakan berada keseimbangan
apabila ia adalah pegun atau dalam keadaan
rehat.
(An object is said to be in equilibriu when it is
stationary or at a rest.) 4
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Titik keseimbangan
Titik keseimbangan
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6. Kedudukan pusat graviti bergantung kepada
bentuk sesuatu objek.
(The position of the centre gravity depends on theshape of the object .)
a) usat graviti objek yang berbentuk sekata adalah
pada pusat simetri objek tersebut. (The centre of gravity of a regular shaped
object is at the centre of the object’s point of
symmetry.)
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Pusat graviti
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b) usat graviti objek berbentuk tidak sekata bolehditentukan dengan menggunakan tali ladung. "itik
persilangan beberapa garis pada objek tersebut ialahpusat gravitinya.
(The centre of gravity of an irregular object can bedeterined by using a plub line. The point of
intersection of the lines will be its centre of gravity .)
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"itik keseimbangan
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PUSAT GRAVITI (CENTRE OF
GRAVITY)
1. usat graviti suatu objek ialah titik di mana gravitibumi yang bertindak ke atas objek tersebut.
(The centre of gravity of an object is the point at
which the earth!s gravity acts on that object.)2. #erat suatu objek ialah disebabkan daya graviti
yang bertindak ke atasnya.
(The weight of an object is due to the gravitationalforce acting on it .)
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3. $aya graviti bertindak ke atas semua
bahagian objek itu% tetapi berat tertumpu pada
satu titik. "itik ini ialah pusat graviti objek.
(The gravitational force acts on all parts of the
object, but the weight can be considered to
concentrate at one point. This point is calledthe centre of gravity of the object.)
4. "itik keseimbangan suatu objek juga adalah
pusat graviti.(The point of equilibriu of an object is also the
centre of gravity.) 10
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!. usat graviti dan titik keseimbangan dide&inisi
sebagai titik di mana seluruh berat objek yangmun'ul untuk bertindak.
(The centre of gravity and the point of equilibriu are
also defined as the point at which the whole weight of
an object appears to act .)
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WongSY@SMKDC
(Pusat graviti)
(Berat)
(Daya graviti)
(Pusat graviti)
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6.Kestabilan suatu objek merujuk
kepada kebolehan objek itu untuk
mengekalkan kedudukan asalnya di
atas tapaknya tanpa tumbang.
(Stability of an object refers to theability of an object to maintain its
original position on a surface without
falling.)
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. Kestabilan sesuatu objek bergantung kepada
a) Kedudukan pusat graviti
b) keluasan tapaknya
') berat objek
The stability of an object depends on"
a) the position of the centre of gravity
b) the base area
c) the weight of the object
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K*$+$+K,- +S," /,0"
( #OS$T$O% O& '%T *A+$T )
ebih stabil apabila pusat gravitinya lebih rendah. (An object is ore stable when its centre of gravity is
low .)
15Keseimbangan Stabil Keseimbangan Tidak
Stabil
Pusat graviti
Pusat graviti
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K*+,S,- ",,K-, ( T- AS AA)
ebih stabil apabila luas tapaknya lebih besar.
( An object is ore stable if its base surface is large.)
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#*/," 5#6*K
(T- /$*-T O& T- O0'T)
-ebih stabil apabila objek lebih berat. (ore stable when the weight of the object is heavy .)
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(Tidak stabil)
(Pusat graviti direndahkan
dengan menambah berat
kepada kelalang)
(Luas tapak besar)
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9.2 KEPENTINGAN KESTABILAN
(IMPORTANCE OF STABILITY)
1. Kestabilan yang berdasarkan kepada pusat graviti yang rendah. (Stability that is based on a low centre of gravity.)
a) 7ai8an besar seperti gajah% badak mempunyai kaki pendek
untuk merendahkan pusat graviti.
(ig anials li1e elephant and rhinoceros have legs that are
short to lower its centre of gravity )
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Gajah (Elephant)
Badak (Rhinoceros)WongSY@SMKDC
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b) Kereta lumba dan pejalan kaki bayi di'ipta dengan
mempunyai badan kereta yang rendah supaya pusat
gravitinya rendah.
(A racing car and baby wal1er are designed to have a body
that is low so that its centre of gravity is low . )
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') enumpangpenumpang sebuah bot dinasihatkan supaya
duduk semasa bot bertolak demi kestabilan bot.
(The pasenggers of a boat are advised to sit while the boat is
oving to aintain the boat2s stability )
d) +nta menurunkan badannya semasa beban dinaikkan atau
diturunkan untuk men'apai kestabilan.
(The cael lowers its body when goods are loaded or unloadedto achieve stability .)
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2. Kestabilan yang berdasarkan kepada keluasan tapak yang
besar.
(Stability is based on a wide surface area.)a) 9ira&a berdiri dengan kakinya terbuka untuk menambahkan
keluasan tapak dan merendahkan pusat gravitinya untuk
men'apai kestabilan.
(*iraffe stands with its legs spread wide apart to increase itsbase area and to lower its centre of gravity to achieve
stability.)
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(Kaki tertutup, pusat graviti
tinggi , kurang stabil)(Kaki buka luas, pusat graviti
rendah, lebih stabil)
c)d)
(Berdiri dengan kaki terbuka
luas)
(Bongkok dan menggunakan
tongkat)WongSY@SMKDC
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(Mengimbangi badan di atas
tali )(membengkok badan dengan
kaki terbuka luas)
(Tumit ang disambung
kepada tapak kasut memberi
kasut luas tapak ang besar
! lebih stabil )
(Tumit ang tidak disambung
kepada tapak kasut memberi
kasut luas tapak ang kecil
" kurang stabil ) WongSY@SMKDC
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5bjek stabil dengan pusat graviti rendahdan luas tapak besar. (Stable objects with a
low centre of gravity and a large base area)
Peralatan Makmal
(Laborator apparatus)
Perabot rumah
(#ome $urniture)
Mainan
(Tos)
Kenderaan
(%ehicles)
WongSY@SMKDC