Definition
Stability of an object is a measure of its ability to return to its original position #PhysicsDefinitions
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| If block is tilted slightly ⇒ it can return back to its original position. vertical line through centre of gravity still falls within its base ⇒ Block weight creates an anticlockwise moment about the pivot that helps block return to original position | If blocks is titled more, it will reach a point where its centre of gravity is in line with the pivot and the block would balance on its edge | Block is tilted even further ⇒ block will topple. Vertical line that passes through centre of gravity → falls outside its base. ⇒ centre of gravity of block will generate a clockwise moment and cause block to topple |
| Stability of object can be affected in 2 ways ⇒ position of centre of gravity and area of base of the object | ||
| → lower the CG → the more stable it is |
same base area but of different lengths
centre of gravity of each block is indicated by CG
When tilted at same angle ⇒ block A topples first
this is because block A has a higher centre of gravity
Vertical line through centre of gravity of block A falls outside its base at a smaller tilt angle
| Answering Techniques for block with lower centre of gravity compared to one with higher centre of gravity |
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| Block B has lower centre of gravity compared to block A. Block B’s line of action of weight through centre of gravity falls outside its base at a much higher tilt angle compared to block A. thus, block B requires more angle of tilt to generate a clockwise resultant moment compared to A. this makes block B more stable than A, making it harder to topple |
| → need to check again!! |
Different base area but same height
centre of gravity labelled at line CG
when slowly tilted at same angle ⇒ Z toppled first
this is because Z has smaller base area
vertical line that passes through centre of gravity of stool Z falls outside its base area at a smaller tilt angle.
Example of toy dragonfly balancing on tip Center of gravity is in line with the pivot (point at which tp rests on stand) ⇒ since centre of gravity (line of action of weight) is directly above pivot ⇒ no moment is generated in any given direction, hence toy does not topple
ADD ANOTHER EXAMPLE LATER