penny in a pool (snell's law)

[cowboys]

Quick question guys.

You're looking into a pool at a penny that is a certain distance from the edge of the pool. Does the image of the penny appear closer or farther than the actual distance of the penny from the edge of the pool? Let's say the angle you look from is 30 degrees from the normal. So, your angle of incidence is 30 degrees. Index of refraction of water is 1.3.

I've seen too many conflicting answers. Please help!

Thanks!

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[Deadlifts]

It's a question of apparent depth. Looking into a medium (water) with greater index of refraction will produce an image at a higher apparent depth. It appears closer to the surface.

A ray diagram really helps visualize it (google image has tons). You're standing at a pool edge and you spot a penny. If you were to dive directly at that penny, you would overshoot the actual penny once you reached the bottom of the pool.

 

[Ansar]

You can just think of how when you look at a straw in your glass of water, it's bent closer to you (if memory serves me correct). So basically it appears closer, because light has been bent toward the normal.

 

[MedGrl@2022]

You can just think of how when you look at a straw in your glass of water, it's bent closer to you (if memory serves me correct). So basically it appears closer, because light has been bent toward the normal.

How about looking straight down on a penny? Would it be perceived to be farther (deeper) because light bends toward the normal? http://physicsed.buffalostate.edu/SeatExpts/EandM/refract/solution.htm

 

[milski]

If you are looking straight down you are looking along the normal, there is no refraction and the perceived depth should be the real one.

 

[Laureatebarrel]

The depth of the image will be less than the actual depth while the distance to the end of the pool will be less.

 

[MedGrl@2022]

The depth of the image will be less than the actual depth while the distance to the end of the pool will be less.

agreed! 🙂 Thanks for bringing this equation up.. I needed practice with ray diagrams! 🙂