Introduction to Waves and Wave Properties

Flashcards covering fundamental wave concepts, classification of transverse and longitudinal waves, quantitative wave properties, and wave phase interference from the lecture notes.

What is the basic definition of a wave?

A disturbance that transfers energy through matter or space.

What is a mechanical wave?

A wave that involves the oscillation of a physical medium, such as water moving up and down in an ocean wave.

How are transverse waves defined?

Transverse waves have oscillations that are perpendicular to the direction of wave propagation.

Why is light classified as a transverse wave?

Light is an electromagnetic wave with electric and magnetic fields oscillating perpendicular to the direction of wave propagation.

How are longitudinal waves defined?

Longitudinal waves have oscillations that are parallel to the direction of wave propagation.

What happens to particle density in a longitudinal wave?

The wave oscillates between regions of compression (high density of particles) and rarefaction (low density of particles).

What is a primary example of a longitudinal wave?

Sound, which consists of pressure waves of air particles hitting the ear.

What is propagation speed?

Propagation speed is the distance traveled by the wave per unit time.

What is the propagation speed of light stated in the transcript?

$$3 \times 10^8\,m/s$$

What is the amplitude of a wave?

Amplitude is the maximum displacement of a wave from zero.

How is the energy of a wave related to its amplitude?

The energy of a wave is directly proportional to the square of its amplitude.

What defines one full wave cycle?

A cycle is the interval required for a wave to return to the exact same point in terms of both position and motion.

What is wavelength?

Wavelength is the distance traveled by a wave in one complete cycle.

What is the period of a wave and what are its standard units?

Period is the amount of time required to complete one cycle, with standard units reported in seconds ($s$).

What is frequency ($f$) and what units are used to measure it?

Frequency ($f$) is the number of cycles completed per second, measured in hertz ($Hz$) or inverse seconds ($\text{s}^{-1}$).

How are period and frequency mathematically related?

Period and frequency are inversely related to each other.

What is phase difference?

Phase difference describes how two waves align relative to each other along their wave cycles.

What occurs when two waves are perfectly in phase?

They align perfectly, experience constructive interference, and combine to form a wave with an amplitude equal to the sum of the original amplitudes ($a_1 + a_2$).

What occurs when two waves are $180^\circ$ out of phase?

They are half a cycle off, experience destructive interference, and combine to form a wave with an amplitude equal to the difference of the original amplitudes ($a_1 - a_2$).

Why is being $360^\circ$ out of phase equivalent to being in phase?

Being $360^\circ$ out of phase represents a full cycle shift, meaning the waves still align perfectly with each other.

What happens when two waves are $90^\circ$ out of phase?

They are one quarter of a cycle off, resulting in constructive interference at some parts of the wave and destructive interference at other parts.