What happens to the colours on the spinner when it is painted with different colours and then spun?
When a spinner painted with different colours is spun, the colours appear to blend together. Due to the rapid spinning motion, our eyes cannot distinguish the individual colours separately, and they merge to create a new visual appearance. This happens because of persistence of vision - the colours mix visually as the spinner rotates quickly.
Explanation
The chapter asks students to 'Colour the spinners in different ways, spin them and observe what happens.' This demonstrates the principle of persistence of vision and colour mixing. When objects spin rapidly, our eyes blend the colours together, creating visual effects that are different from the stationary spinner.