How Is the Sun's Angle of Inclination Calculated from Underwater?

[akmphy]

Angle of Inclination: ?

Homework Statement

An underwater scuba diver sees the Sun at an apparent angle of 23 degrees from the vertical. The refraction index for water is 1.32. what is the Sun's angle of inclination?

Homework Equations

n1sin(degree)= n2sin(degree)

The Attempt at a Solution

1.32sin(23) = 1sin(degree)
sin-1 (.51576) = 31.04
This was the wrong answer. I thought this was straightforward. I must be missing something here.

 

[Doc Al]

Your work looks fine to me. Are you sure they want the Sun's angle of inclination from the vertical?

 

[akmphy]

The problem asks for the Sun's angle of inclination?
wouldn't that be the angle it strikes the surface of the water?

 

[Doc Al]

The problem asks for the Sun's angle of inclination?
wouldn't that be the angle it strikes the surface of the water?

That's what I would say. Measured from the horizontal, not the vertical.

 

[akmphy]

So, I tried that...
90-31.05 = 58.95
This was wrong as well.

 

[Doc Al]

If this is an online system, they can be picky about significant figures.

(If it's from a textbook, tell me which one and what problem.)

 

[akmphy]

It is an online UT program. Do you think the set up is correct? I will e-mail professor to double check.

 

[Doc Al]

As I said, your work looks fine to me. The only ambiguity is whether the inclination of the Sun is with respect to the horizontal or not. But that doesn't explain your experience with the online system.

 

[akmphy]

I wish I was more savvy with the computer. The angle desired is with respect to the horizontal...the water surface.
However, it must be a glitch. That would be 90-31.05, which was wrong.
Thanks for your help