Harmonic WaveD(x)=Asin(kx) (t=0)

Terms to understand Harmonic wave: wave going through

simple harmonic motion Amplitude: the max displacement on a

graph to the equilibrium point Crest: Point on graph with maximum

displacement Trough: Point on graph with minimum

displacement

Wavelength: Shortest distance between two points that repeats itself.

Wavenumber: Parameter K in the wave equation.

- How does K relate to the wavelength?A wave repeats itself after every wavelength. D(x)= D (x+λ (wavelength) ). Plug this into the equation. D(x)= Asin(kx) Asin(k(x+λ))Asin(kx+kλ) In the sine function, wavelength is 2pi. Therefore 2pi=kλ and k=2pi/λ

Wave and SpeedKey equation: V=λfUsing this equation, we could find a relationship between k=2pi/λ and f=w/2pi. V=λf= (2pi/k)(w/2pi) = w/k F=1/period(T)

Question 1- Use the following graphs to answer the question

Graph of radio wave 1. Period for each rotation 3s

Graph of radio wave 2. Period for each rotation is 4 seconds.

Question 1 Using the key equations and graphs,

What is the wave speed of: A)Frequency of radio waves 1 and 2 B) Wavelength’s of radio wave 1 and 2

(in meters)? C) Which radio wave has a higher

velocity?

Solutions A) Use formula F=1/T- Radio wave 1: F=1/(3sec)= 0.33Hz- Radio wave 2: F=1/(4sec)= 0.25Hz B) Wavelengths- the shortest distance at which

graph repeats. - Radio wave 1: 2m- Radio wave 2: 3m C) Velocity =wavelength x frequency - Radio wave 1: V=0.33x2= 0.66m/s- Radio wave 2: V=0.25x3= 0.75m/s- Radio wave 2 has a faster velocity than radio

wave 1