Where did the Coin come from?

Introduction :

Refraction of light shows up in many ways in daily life. When light traveling in one medium falls on the surface separating it from another transparent medium, it bends according to Snell’s Law. This shows up in various ways in daily life. In this experiment we give one interesting way to feel this.

Procedure:

1. Place an empty steel glass on the table and place a coin at the bottom of the glass at the center.
2. Stand close to the table. You can see the coin. Now go back to a position from where the coin just becomes invisible.
3. Ask your friend to put water in the glass. As the water is filled, at some stage coin becomes visible.

Discussion :

As the light from the coin comes to water surface, it bends away from the normal. Thus light which was earlier going from above the eye now reaches the eye after refraction. This makes the coin visible.

Hazard :

None