Physics: Waves & Optics

What is the fundamental relationship between wave speed (v), frequency (f), and wavelength (λ)?

v = fλ

In a transverse wave, what is the geometric relationship between the direction of particle oscillation and the direction of wave propagation?

The particles oscillate perpendicular to the direction of wave propagation.

According to the Law of Reflection, how does the angle of incidence relate to the angle of reflection?

The angle of incidence is equal to the angle of reflection (θi = θr), both measured from the normal.

Which region of the electromagnetic spectrum possesses the longest wavelengths and lowest frequencies?

Radio waves.

How is the index of refraction (n) of a material defined in relation to the speed of light?

n = c/v, where c is the speed of light in a vacuum and v is the speed in the medium.

What term describes the number of wave cycles that pass a fixed point per unit of time?

Frequency (measured in Hertz).

What two conditions must be met for total internal reflection to occur?

1. Light must travel from a medium with a higher refractive index to one with a lower index. 2. The angle of incidence must exceed the critical angle.

Describe the change in observed frequency when a sound source moves toward a stationary observer.

The observed frequency increases (higher pitch) because the wavefronts are compressed in front of the source.

State Snell's Law and explain what it predicts.

n1 sin(θ1) = n2 sin(θ2); it predicts the degree of refraction when light crosses a boundary between two media.

What phase change, if any, occurs when light reflects off a boundary with a medium that has a higher refractive index?

A phase shift of 180 degrees (or π radians) occurs.