Physics·General Physics · NSSCO 2.8
Centre of mass & stability
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Every object balances at one special point — the centre of mass, where all its weight seems to act. In this lesson we find that point for an awkward shape using the plumb-line method, then use it to explain stability: why some objects spring back when tilted, others topple, and why a wide base and a low centre of mass make an object so hard to knock over.
What you'll learn in this lesson
By the end you should be able to (NSSCO Physics 2.8):
- Describe the centre of mass (centre of gravity) as the single point where all the weight of an object seems to act
- Describe an experiment to determine the position of the centre of mass of a plane lamina using a plumb line
- Describe the effect of the position of the centre of mass and the size of the base on the stability of simple objects
- Distinguish between stable, unstable and neutral equilibrium
- Explain, using the line of action of the weight and the base, why wide, low objects are hard to topple
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Ms Elizabeth and Mike talk through the whole topic — with the figure and working drawn live.