Chapter 29, Problem 18A

If you can see the face of a friend who is underwater, can she also see you?

To determine

To Explain: Whether a person underwater can see another person’s face who is outside the water.

Answer to Problem 18A

Yes, she can see you because of refraction of light.

Explanation of Solution

Introduction: Change in the direction of light or bending of light when it (light) travels from one medium to different medium, known as Refraction.

It is known that the path of lights is reversible for refraction and reflection. These two processes help in seeing underwater. So, if you can see the face of a friend who is underwater, she can also see yours face too.

Conclusion: Yes, a person underwater can see another person’s face who is outside the water.