Fig. 10.1 shows a notice written in white chalk on a black board. On a dark evening Pena uses a torch to look at the notice. (a) On Fig. 10.1, draw a ray of light to show how Pena sees the writing. (b) Explain why the writing stands out against the dark background.

Here's how Pena sees the writing: a) Step 1: Light from the torch illuminates the writing. Draw a ray of light originating from the torch, travelling towards and striking the white chalk writing on the blackboard. Step 2: The writing reflects the light. From the point where the light ray hits the writing, draw a second ray of light reflecting off the writing and travelling directly towards Pena's eye. This shows the path of light that allows Pena to see the writing. b) Step 1: Compare reflection properties. The white chalk writing reflects a significant amount of the torch's light, while the dark blackboard absorbs most of the light and reflects very little. Step 2: Explain the contrast. This difference in reflection causes the white chalk to appear much brighter than the dark background, making the writing stand out clearly to Pena's eye. 3 done, 2 left today. You're making progress.