Law of reflection:

angle of reflection = angle of incidence

*with respect to Normal

Equation to determine index of refraction:

n = ^{c}/_{v}

What happens to light as a goes from a less dense medium (small index of refraction) to a more dense medium (higher index of refraction)?

wavelength becomes shorter, the wave travels slower

**Bends toward Normal**

What happens to light as a goes from a more dense medium (high index of refraction) to a less dense medium (lower index of refraction)?

wavelength increases, light ray travels faster

**Bends away from Normal**

Energy of a photon equation:

E = hf

Equation to determine wavelength:

λ = ^{c}/_{f}

Snell's Law:

n_{1}sinθ_{1} = n_{2}sinoθ_{2}

describes angle of refraction in relation to index of refraction. As the angle of refraction increases, the index of refraction decreases.

What wavelengths of light are most affected by refraction?

shorter wavelengths:

Violet will refract the most and red will refract the least; the frequency never changes, only the wavelength does

A converging system is one in which light rays:

converge

A diverging system is a system in which light rays:

diverge

The two converging systems:

concave mirrors

convex lens

The two diverging systems:

convex mirror

concave lens

Equation to determine focal length from object distance and image distance:

^{1}/_{f} = ^{1}/_{o} + ^{1}/_{i}

f = focal distance in m

o = object distance in m

i = image distance in m

Equation to determine magnification:

m = -^{i}/o

|m| < 1 = reduced

|m| > 1 = magnified

|m| = 0 = same size

-m = inverted

+m = upright

|m| < 1 =

reduced

|m| > 1 =

magnified

|m| = 0 =

same size

-m =

inverted

+m =

upright

focal length for spherical mirrors (concave or convex):

f = ^{1}/_{2}r

r = radius of curvature in m

Three rules for converging mirrors and lenses:

Converging = concave mirrors and convex/convex lenses:

1) **F < o = IR **(inverted / real)

2) **F = o = NO **(no image)

3) **F > o = UV **(upright / virtual)

Single rule for diverging mirrors and lenses:

diverging = convex mirrors and concave/convex lenses:

1) **UV _{min} **(upright / virtual / minimized)

Converging mirror and lenses magnification rules:

1) **2f > o > f = enlarged**

2) **2f = o = same size**

3) **2f < o = minimized**

When is f positive and negative?

positive = converging

negative = diverging

When is i positive and negative?

positive = real

negative = virtual

When is o positive and negative?

positive = same side as light ray

negative = opposite side of light ray

When is m positive and negative?

positive = upright

negative = inverted

Chromatic aberration cause:

dispersion of light due to refraction; only applicable to lenses

Spherical abberation cause:

imperfections in the spherical surface of a lens or mirror

less spherical = more imperfections

For a combination lens system, what is the total magnification?

M_{total} = (m_{1})(m_{2})

Equation to determine the critical angle:

sin(θ_{c}) = ^{nr}/_{ni}

nr = the refractive medium

ni = the incident medium

When light hits a medium at an angle equal to or greater than the critical angle, what occurs?

total internal reflection; the light ray is reflected back into the incident medium