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A uniform solid hemisphere has radius 8 cm. At what distance (in cm) from the centre of its flat circular face does its centre of mass lie?

1. 2
2. 3
3. 4
4. 5

Correct answer: 3

Solution

For a uniform solid hemisphere the centre of mass lies on the symmetry axis at 3R/8 from the flat face, giving 3 cm for R = 8 cm.

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