The Nature of Waves

Properties of waves are introduced as we explore the wave velocity equation by finding the frequency and wavelength of different types of waves. Simple harmonic motion is introduced with a discussion of spring force and spring potential energy and how that motion relates to waves.

Unit 6 Segment A: The Nature of Waves Properties of waves are introduced as we explore the wave velocity equation by finding the frequency and wavelength of different types of waves. Simple harmonic motion is introduced with a discussion of spring force and spring potential energy and how that motion relates to waves.

Premiere Date: July 31, 2018 | Runtime: 00:10:17

## Learning Objectives

-Compare and contrast the properties of transverse waves and longitudinal waves.

-Understand simple harmonic motion and how it relates to spring potential energy and use the spring constant successfully in calculations.

-Explain how simple harmonic motion and wave motion are related.

-Compare and contrast equilibrium position, period, amplitude, wavelength, and frequency conceptually and mathematically for a pendulum and a spring.

## Vocabulary

amplitude - the distance from the equilibrium position to the maximum or minimum intensity of a wave.

electromagnetic wave - oscillating electric and magnetic fields that need no physical medium through which to travel.

frequency (f) - the number of wavelengths that pass a given point per second; SI unit is the Hertz (Hz).

harmonic motion - the repetition of a wave with a constant frequency.

longitudinal wave - a wave that vibrates in the direction of propagation (e.g. sound waves).

mechanical wave - a wave requiring a physical medium through which to travel.

period (T) - the time it takes for one wave cycle to occur; SI unit is seconds (s).

spring constant (k) - a characteristic of a spring that is equal to the force exerted on it divided by the displacement the spring stretches; the unit is Newton/meter (N/m).

spring force (FS) - this force is equal to the spring constant, k, for a given spring multiplied by the displacement the spring is stretched from the equilibrium position, x.

spring potential energy (PES) - the amount of stored energy in a spring and is equal to one half times the spring constant, k, times the displacement the spring is stretched from the equilibrium position, x, squared.

transverse wave - a wave that vibrates perpendicular to the direction of propagation (e.g. electromagnetic waves).

wavelength (λ) - The distance between two waves that includes on full compression and one full rarefaction of a sound wave or one full crest and one full trough of an electromagnetic wave; SI unit is meters (m).

## Georgia Standards of Excellence

SP4Obtain, evaluate, and communicate information about the properties and applications of waves.

SP4.aDevelop and use mathematical models to explain mechanical and electromagnetic waves as a propagating disturbance that transfers energy. (Clarification statement: Mathematically describe how the velocity, frequency, and wavelength of a propagating wave are related.)

SP4.cConstruct an argument that analyzes the production and characteristics of sounds waves. (Clarification statement:Includes, but not limited to, Doppler Effect, standing waves, wavelength, the relationship between amplitude and the energy of the wave, and the relationship between frequency and pitch.)

SP4.dPlan and carry out investigations to characterize the properties and behavior of electromagnetic waves. (Clarification statement: Properties of waves include, but not limited to, amplitude, frequency, wavelength, and the relationship between frequency or wavelength and the energy of the wave.)

SPS9Obtain, evaluate, and communicate information to explain the properties of waves.

SPS9.aAnalyze and interpret data to identify the relationships among wavelength, frequency, and energy in electromagnetic waves and amplitude and energy in mechanical waves.

SPS9.bAsk questions to compare and contrast the characteristics of electromagnetic and mechanical waves.

SPS9.cDevelop models based on experimental evidence that illustrate the phenomena of reflection, refraction, interference, and diffraction.

SPS9.dAnalyze and interpret data to explain how different media affect the speed of sound and light waves.

S8P4Obtain, evaluate, and communicate information to support the claim that electromagnetic (light) waves behave differently than mechanical (sound) waves.

S8P4.aAsk questions to develop explanations about the similarities and differences between electromagnetic and mechanical waves. (Clarification statement: Include transverse and longitudinal waves and wave parts such as crest, trough, compressions, and rarefactions.)

S8P4.bConstruct an explanation using data to illustrate the relationship between the electromagnetic spectrum and energy.

S8P4.cObtain, evaluate, and communicate information to explain practical applications of the electromagnetic spectrum (e.g., communication, medical, military).

S8P4.dDevelop and use a model to compare and contrast how light and sound waves are reflected, refracted, absorbed, diffracted, or transmitted through various materials. (Clarification statement: Include echo and how color is seen but not interference and scattering.)

S8P4.eAnalyze and interpret data to predict patterns in the relationship between density of media and wave behavior (i.e., speed).

S8P4.fDevelop and use a model (e.g., simulations, graphs, illustrations) to predict and describe the relationships between wave properties (e.g., frequency, amplitude, and wavelength) and energy.

S8P4.gDevelop and use models to demonstrate the effects and functions of lenses.

## Request Teacher Toolkit

The Physics in Motion teacher toolkit provides instructions and answer keys for study questions, practice problems, labs for all seven units of study.  GPB offers the teacher toolkit at no cost to Georgia educators. It will be available in September 2018. To preorder your teacher toolkit, complete and submit this form to request the teacher toolkit. You only need to submit this form one time to get materials for all seven units of study.