Waves and Energy

sound, light*,water seismic (earthquakes)

Draw a mind map for waves and energy

Describe the characteristics of the wave.

Mexican Wave clip

Properties of Waves

A wave is a transfer of energy from one point to another with out the transfer of

material between the two points.

and sound waves from a speaker

Main properties of waves

Other termsPeriod (T) units seconds (s), frequency (f) units hertz (Hz)

speed (v) units metre/second (m/s) Text Pages 4 - 15

Calculations

• Frequency = 1/period f = 1/T unit Hertz (Hz)

• Speed = wavelength x frequencyv = l f unit metre/second (m/s)

Assume speed in air 340 m/s unless told other wise.

Transverse Waves

water waves, light waves*, some seismic waves •In groups role model the movement of particles in a transverse wave e.g. water wave

Text Page 6 – 8, 27•Creating a transverse wave

Transverse Wave

Longitudinal Wave

sound waves and some seismic waves•In groups role model the movement of particles in a longitudinal wave e.g. sound wave

Text Pages 9 – 10,27

compression rarefaction

Creating a longitudinal wave

Tuning ForksTask : Strike each tuning fork on the bench and comment on its sound (pitch, loudness and intensity)Perceptive and subjective qualities of sound.• Pitch is how high or low a sound seems (lion low, bird high)• The louder the sound the more energy the sound wave has.• Intensity is also linked to how high and often a wave occurs.

Text Page 42 - 45

Key word links

amplitude frequency loudness Pitch period wavelength Intensity

Speed of SoundMaterial

Speed of Sound

estimateSpace

Vacuum No sound

Rubber at 20oC 60 m/s

Air at 40oC 355 m/sAir at 20oC 343 m/s

Water at 20oC 1500 m/sGlass 4540 m/s

Steel at 20oC 4800 m/sAluminum 5000 m/s

Speeds of Sound

Text book page 39

http://www.ndt-ed.org/EducationResources/HighSchool/Sound/speedinair.htm

Speed of sound • Explain why the speed of sound is not

constant (the same) for all materials.

Draw waves to represent the following sounds

• Soft low frequency sound

• Loud high frequency sound

• Short wavelength loud sound

Describe the two waves below

Sound from a Speaker

Loud speaker simulation

Components of a speaker

Sound intensity level and distance

Sound waves spread out in all directions decreases intensity.

Complete Review Properties of Waves

• Draw wave diagrams where needed • Show all working• Remember to place units on calculations• Explanations may be in point form.

Hearing

Ears work in a similar way to speakers.

Frequencies at which a range of animals can hear

Interaction of waves with boundaries

Reflection

Prove: angle of incidence = angle of reflection

Use light boxes to prove this rule

Task

Assessment: Criteria F

Interaction of waves with boundaries

RefractionBending and change of speed of waves as they pass from one medium to another.Task Investigate light waves moving from air to plastic.Assessment criteria D and E

Summary of Interaction between boundaries

Lines represent rays of light

How does Homer see the box?

Reflection

Specula Reflection Smooth surfaces the waves are not spread out

Diffuse Reflection

Irregular surface means thewaves are spread out

Electromagnetic WavesAn electromagnetic wave consists of vibrating electric and magnetic fields

that move through space at the speed of light.

The smaller the wavelength the greater their energy

These waves can transfer energy with out a medium to travel through.

You are only expected to know the basics structure and chacteristics of EM

waves.

Chapter 3 pages 70 – 71, 74 - 75

Page 74Page 74 - 75

Waves around us and their usesSound Microwaves

Sound is used to find objects and depth of oceansSound barriers use the ideas of reflection to Stop sound pollution

Microwaves are used in modernCommunicationFibre optics instead of using wiresSimilar many controls around the house use Microwaves to operate systems.

Page 62

Pages 90 - 93

Waves and our atmosphereDifferent wavelength can be used for different types of communication from contacting ET to phoning home.

Waves and HealthUltra sound 20 kHz used in the same way as echo sounding.

High frequency waves provide heat to help healing.

Page 63

X rays are used to to obtain images of solids for example bones

Page 79

Review Questions from TextChapter 1 Questions Section 1 Assessment page 10 Question 2 CSection 2 Assessment page 15 Questions 1 & 2Section 3 Assessment page 23 Questions 1 bChapter 1 Review and Assessment Review Key terms Question 1 – 4Chapter 1 Review and Assessment Question 9, 11, 12, 16, 17, 18, 19,

22- 25Chapter 1 Standardised test prep Questions 1- 3, 6

Review Questions from Text

Chapter 2 Questions Section 1 Assessment page 41 Question 1, 2 b,c, Section 2 Assessment page 47 Questions 1 a, b, 2 a, b, Section 5 Assessment page 63 Questions 1 c, 2 a, b, cChapter 2 Review and Assessment Review Key terms

Question 2, 5Chapter 2 Review and Assessment Question 11, 13, 16,

199, 11, 12, 16, 17, 20, 21, 23, 25Chapter 2 Standardised test prep Questions 1, 2, 4,

Review Questions from Text

Chapter 3 Questions Section 1 Assessment page 73 Question 1 a, b Section 2 Assessment page 81 Questions 1 a, c, 2 a,

b, cChapter 3 Review and Assessment Review Key terms

Question 1, 3, Chapter 2 Review and Assessment Question 11, 14,

25, 26, 27Chapter 2 Standardised test prep Questions 3, 5,

Review Questions from Text

Chapter 4 Questions Section 2 Assessment page 118 Questions 1 a,b,cSection 2 Assessment page 123 Questions 1bChapter 4 Review and Assessment Review Key

terms Question 2,Chapter 2 Review and Assessment Question 16Chapter 2 Standardised test prep Questions 1, 3,