CHAPTER 9 : STABILITY

GLOSSARY


1.Base (Tapak) - The lowest part of an object on which the object rests or is supported


2. Base area (Luas tapak) - The surface covered by the base


3. Centre of gravity (Pusat Graviti) - The point of an object at which the whole weight of the seems to act.


4. Equlibrium (Keseimbangan) - A state of balance


5. Point of intersection (Titik persilangan) - Point where two or more lines cut or crossed each other.


6. Stability (Kestabilan) - The ability of an object to remain in its original position when disturbed.


7. Stable (Stabil) - Not likely to topple or change position.


UNIT 9.1 : STABILITY


1. The point of equilibrium is the point where the whole weight of an object appears to act on.


2. It is the point in which an object can be balanced on and it is present in all objects.


Activity 1


Make a triangle, a circle and a rectangular and find the point of eqilibrium. 


3. The point of equlibrium of an object is actually the centre of gravity pf the object.


4. It is the point at which the Earth's gravity acts on an object.


Factors affecting the stability of an object


1. The position of the centre of gravity


"The lower the centre of gravity, the more stable the object"


2. The base area


"The wider the base area, the more stable the object"


UNIT 9.2 : IMPORTANCE OF STABILITY


1. The principle of stability is applied to many aspects of our daily life.


2. We are more stable when we are standing with our legs apart because the centre of gravity is lower and the base area is wider.


3. An old man increases his stability by using walking stick.


4. A crawling baby is stable because his centre of gravity is low and his base area is wide.


5. A crocodile is more stable than a giraffe because its centre of gravity is lower.


6. A giraffe stands with its legs wide apart to increase its base area and to lower its centre of gravity.


7. Animals with heavy bodies have shorter legs to lower their centre of gravity.


8. A racing car is stable because it has low centre of gravity, wide tyres and wide base area.


9. Engines of lorries and buses are heavy and are placed underneath the vehicles to lower their centre of gravity.


10. Laboratory apparatus such as Bunsen Burner, retort stand and measuring cyclinder have wide bases to increase stability.


11. Motorcycle riders bend their body forward when they are speeding. This is to lower the centre of gravity of the rider and his motorcycle.


12. To maintain the stability of a double-decker bus, passengers are advised to fill up the empty seats in the lower deck first.


13. Passengers in a boat are advised to sit down instead of standing so as to lower the centre of gravity the boat.


14. Extra wheels are attached to children's bicycle to increase their stability.