# Homework Help: Refraction - Spherical Surface

1. Mar 11, 2012

### oddwolf

1. The problem statement, all variables and given/known data

A 2 meter deep swimming pool is filled with water. A mirror is placed at the bottom and a small fish swims 5 cm (0.05m) below the surface. If you look at the swimming pool from above, how deep does the fish appear to be (a), and how deep does it's image appear to be (b)?

a1 = 0.05 m
a2 = 2.00 m
n_air = 1
n_water = 1.33

2. Relevant equations

n1/a1 + n2/a2 = (n2 - n1)/r

3. The attempt at a solution

Not so sure with (a), but without using the formula or anything on (b), my intuition tells me that the mirror-image should be 15+15+5 centimetres below the surface. Would really appreciate some help with (a) and some input.

2. Mar 11, 2012

### ehild

Is any spherical surface mentioned in the problem?

ehild

3. Mar 11, 2012

### oddwolf

The only hint my book gave me is to use the formula for refraction in spherical surface.

4. Mar 11, 2012

### ehild

Last edited: Mar 11, 2012
5. Mar 11, 2012

### rktpro

And you can derive hell lot of equations from what ehild provided you. :D