A fish swims below the surface of the water at point P A fish swims below the surface of the water at point P. An observer at point O sees the fish at: 1) a greater depth than it really is 2) the same depth 3) a shallower depth than it really is

A fish swims below the surface of the water at point P A fish swims below the surface of the water at point P. An observer at point O sees the fish at: 1) a greater depth than it really is 2) the same depth 3) a shallower depth than it really is

A fish swims below the surface of the water A fish swims below the surface of the water. Suppose an observer is looking at the fish from point O, which is directly above the fish. The observer sees the fish at: 1) a greater depth than it really is 2) the same depth 3) a shallower depth than it really is

A fish swims below the surface of the water A fish swims below the surface of the water. Suppose an observer is looking at the fish from point O, which is directly above the fish. The observer sees the fish at: 1) a greater depth than it really is 2) the same depth 3) a shallower depth than it really is

To shoot a fish with a gun, should you aim directly at the image that you see, slightly above the image, or slightly below it? 1) aim directly at the image 2) aim slightly above 3) aim slightly below

To shoot a fish with a gun, should you aim directly at the image slightly above or slightly below? 1) aim directly at the image 2) aim slightly above 3) aim slightly below You will see the fish at a position above its actual position, so you should aim below this image.

To shoot a fish with a laser pistol, should you aim directly at the image slightly above or slightly below? A) aim directly at the image B) aim slightly above C) aim slightly below, about where you would aim a gun D) aim even further below than you would aim with a gun

light from fish laser beam To shoot a fish with a laser pistol, should you aim directly at the image slightly above or slightly below? A) aim directly at the image B) aim slightly above C) aim slightly below, about where you would aim a gun D) aim even further below than you would aim with a gun The light from the laser beam will also bend when it hits the air-water interface, so aim directly the fish.

An observer views two closely spaced lines through an angled piece of glass. To the observer, the lines appear: 1) shifted to the right 2) shifted to the left 3) spaced farther apart 4) spaced closer together 5) no change -- exactly as before

1 v1t 2 v2t

1 v1t i h i r 2 v2t r

Snells’ Law We can classify materials by their “index of refraction” defined as the ratio of speed of light in a vacuum, c speed of light through medium, v i.e. Note then that: reversing the indices! So often Snell’s Law is also written as: n1sin1 = n2sin2

A ray of light is shown entering a glass prism, bending down (toward the normal) as it enters. As the ray re-enters the air through the opposite face of the prism it bends up. it passes through without bending. it bends further down.

A ray of light is shown entering a glass prism, bending down (toward the normal) as it enters. Glass-into-air: light bends away from normal Air-into-glass: light bends toward normal As the ray re-enters the air through the opposite face of the prism it bends up. it passes through without bending. it bends further down.