Chapter 23, Problem 10Q

To determine

To draw:

The ray diagram that shows why a stick or a straw bent when part of it is under water.

Answer to Problem 10Q

Solution:

The ray diagram that shows stick or a straw bends if it is under water

Explanation of Solution

A part of the straw is dipped into the water. To the person, who sees it from outside it appears bends.

The person’s view can be analyzed as follows:The light ray, at the bottom of the straw (ray 2),when it reaches the boundary of the water, bends away from the normal due to the refraction. But, the person interprets that it appears to come from the point A.

In the same way, the ray 3 bents away at the surface of the water and the person views this appears from the point B.

The person can view the straw along AB, shallower than it really is, so it looks bent.

Each point on the straw that is underwaterappears to the person to be closer to the surface than it actually is.