Coin in water

This task is about investigating light rays in water. 
Practical task
  1. Put the bowl on a desk and put the coin in the bottom nearest the edge facing you.
  2. Look at the coin and walk slowly backwards until it disappears from view.
  3. Now, get your partner to slowly pour water into the bowl without moving the coin while you are still looking at it.
  4. Swap positions and try the experiment a few more times.

Question 1Change answer

a)  What happens when the water is poured into the bowl?

Question 1Change answer

b)  Explain why you think this has happened?