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,