Question

A tank whose bottom is a mirror is field with water to a depth of 20cm a small object hange 8cm under the surface of water. What is the apparent depth of its image when viewed at normal incidence

Answer 1

Step 1

1. The object is 8 cm below the water surface.

Step 2

2. The light from the object travels through the water to the mirror at the bottom of the tank.

Step 3

3. The light reflects off the mirror and travels back through the water to the observer.

Step 4/4

4. The observer sees the image of the object as if it were at a certain depth below the water surface. Since the index of refraction for water is given as n = 4, we can use the formula for apparent depth: Apparent depth = (Actual depth) / n In this case, the actual depth is the distance from the object to the mirror, which is 20 cm - 8 cm = 12 cm. Now we can find the apparent depth: Apparent depth = (12 cm) / 4 Apparent depth = 3 cm However, this is the apparent depth of the object from the mirror. To find the apparent depth of the object from the water surface, we need to add the actual depth of the object from the water surface: Total apparent depth = Apparent depth + Actual depth of object from water surface Total apparent depth = 3 cm + 8 cm Total apparent depth = 11 cm So, the apparent depth of the object when viewed at normal incidence is $\boxed{11\text{ cm}}$.