# PH.8 - Wave Phenomena

The student will investigate and understand wave phenomena. Key concepts include

a)  wave characteristics;

b)  fundamental wave processes; and

c)  light and sound in terms of wave models.

Bloom's Levels:  Analyze; Understand

### BIG IDEAS

• I can explain why a glass will shatter at certain frequencies.
• I can tell when a singer is out of tune with the music.
• I can explain why its difficult to hear people when I'm under water.

### UNDERSTANDING THE STANDARD

The concepts developed in this standard include the following:

• Mechanical waves transport energy as a traveling disturbance in a medium.
• In a transverse wave, particles of the medium oscillate in a direction perpendicular to the direction the wave travels.
• In a longitudinal wave, particles of the medium oscillate in a direction parallel to the direction the wave travels.
• Wave velocity equals the product of the frequency and the wavelength.
• For small angles of oscillation, a pendulum exhibits simple harmonic motion.
• Frequency and period are reciprocals of each other.
• Waves are reflected and transmitted when they encounter a change in medium or a boundary.
• The overlapping of two or more waves results in constructive or destructive interference.
• When source and observer are in relative motion, a shift in frequency occurs (Doppler effect).
• Sound is a longitudinal mechanical wave that travels through matter.
• Light is a transverse electromagnetic wave that can travel through matter as well as a vacuum.
• Reflection is the change of direction of the wave in the original medium.
• Refraction is the change of direction of the wave at the boundary between two media.
• Diffraction is the spreading of a wave around a barrier or an aperture.
• The pitch of a note is determined by the frequency of the sound wave.
• The color of light is determined by the frequency of the light wave.
• As the amplitude of a sound wave increases, the loudness of the sound increases.
• As the amplitude of a light wave increases, the intensity of the light increases.
• Electromagnetic waves can be polarized by reflection or transmission.
• Polarizing filters allow light oriented in one direction (or component of) to pass through.

### ESSENTIALS

In order to meet this standard, it is expected that students will

a)  identify examples of and differentiatebetween transverse and longitudinal waves, using simulations and/or models.

illustrate period, wavelength, and amplitude on a graphic representation of a wave.

solve problems involving frequency, period, wavelength, and velocity.

b-c) distinguish between superimposed waves that are in-phase and those that are out-of-phase.

graphically illustrate reflection and refraction of a wave when it encounters a change in medium or a boundary.

graphically illustrate constructive and destructive interference.

identify a standing wave, using a string.

### KEY VOCABULARY

Updated: Dec 01, 2017