Parts of a Wave

Simple and to the pointSimple and to the point

Amplitude The height of the wave at any

point is called its amplitude.

Crest The crest is the part of the wave The crest is the part of the wave

with the greatest amplitude.with the greatest amplitude.

Trough The trough is the part of the waveThe trough is the part of the wave

with the lowest amplitude.with the lowest amplitude.

Node A node is a point of zero amplitude. A node is a point of zero amplitude.

In the drawing below, the nodes In the drawing below, the nodes are are

where the orange waves intersectwhere the orange waves intersect

with the green baseline.with the green baseline.

WavelengthWavelength, (Wavelength, (λλ), is the straight line ), is the straight line distance between two consecutive distance between two consecutive peaks. It can also be the difference peaks. It can also be the difference between any two corresponding between any two corresponding points, like two troughs.points, like two troughs.

Wave Properties: Period The wave period, (P), is the time it The wave period, (P), is the time it

take one wave to pass the take one wave to pass the observer. It is a unit of time.observer. It is a unit of time.

Wave Properties: Frequency Frequency, (Frequency, (νν)), is the number , is the number

of waves passing a particular of waves passing a particular point in one second.point in one second.

Examples of Frequency

What is the frequency of the What is the frequency of the second second hand of a clock ?hand of a clock ?

Frequency = 1 cycle/60 secondsFrequency = 1 cycle/60 seconds

Period = 60 secPeriod = 60 sec

What is the frequency of the FIFA What is the frequency of the FIFA World Cup ?World Cup ?

Frequency = 1 tournament /4 Frequency = 1 tournament /4 yrsyrs

Period = 4 yrsPeriod = 4 yrs

The Doppler Effect # 1 Refers to the change in frequency when there is relative motion

between an observer of waves and the source of the waves. Notice the waves are more compressed on the right diagram. No Motion Motion to the rightNo Motion Motion to the right

The Doppler Effect # 2

The Doppler Effect is an interesting look at The Doppler Effect is an interesting look at how waves behave. We have all observed how waves behave. We have all observed the Doppler Effect. When a car is coming the Doppler Effect. When a car is coming at us with a horn blowing, the horn sounds at us with a horn blowing, the horn sounds different as it is coming at us then it does different as it is coming at us then it does when it is moving away from us.when it is moving away from us.

Doppler with SoundDoppler with Sound

EXTRA CREDIT

Let’s see who has looked at this Let’s see who has looked at this slideshow.slideshow.

The first person that writes the The first person that writes the following on a piece of paper and following on a piece of paper and hands it in to me will get 25 hands it in to me will get 25 homework points.homework points.

““Waves are wonderful.”Waves are wonderful.”