waves, sound, electromagnetic radiation
DESCRIPTION
Waves, sound, Electromagnetic Radiation. Conceptual Physics . To do…. See how many of the quiz topics you can answer as a table group (if you don’t know the answer right away, seek out the answer with your notes/webquests/EM poster) - PowerPoint PPT PresentationTRANSCRIPT
Waves, sound, Electromagnetic Radiation
Conceptual Physics
To do… See how many of the quiz topics you
can answer as a table group (if you don’t know the answer right away, seek
out the answer with your notes/webquests/EM poster)
Identify which questions your table can’t answer
Pick your top 2 topics that you need to review today…
Self-grade… Go over answers on your webquests 18 pts each answer
Shows example of a wave (indicating change in wavelengths)
2
Arrows showing areas of higher and lower wavelengths, frequencies and energy.
6
The six types of EM Waves discussed in class
6
Drawings/pictures that represent the type of wave
6
Accurate ratios and division of page 2
Creative/Artistic/Colorful/Neat/Professional 5
Totals /27
4 square notes 5 pts each page Definition = 1 Real world ex = 2 Picture = 1 3-5 facts = 2
Total = 30 pts
Radio Infrared Visible light Uv X-rays Gamma rays
Next 10 minutes Interactive review
Do NOT write for next 10 minutes
Stop – share with table group all the information you think is important for quiz, what information was clarified for you
Wave Basics
Key Vocab.-Amplitude: The maximum displacement of a wave from equillibrium (height of a wave)-Wavelength: The length of one full wave cycle or repetition -Period: The amount of time it takes a wave to complete one full cycle-Frequency: The number of wave vibrations/repetitions per second (Hz)-Equilibrium: The resting place of a wave with no disturbance-Crest: The highest point or peak of a wave-Trough: The lowest point or bottom of a wave
Crest
Trough
Line of Equilibrium
Basics Waves- traveling disturbance that
carries energy (not matter) Boat/wave example
Energy = ability to do work Vibration: any movement follows
same path repeatedly Ear drum, drum, earthquake
Vibrate – particle moving – produces energy – transfers energy to nearby particles – wave Ocean, ropes, sound, microwaves
?
?
Waves… a reviewMost waves are either
longitudinal or transverse.Sound waves are longitudinal.But all electromagnetic waves
are transverse…
Wave Types A wave is a traveling disturbance that transfers energy. 2 Types of Waves:
Transverse: side to side wave sending vibration perpendicular to the medium
Longitudinal: push & pull wave sending vibration parallel to the medium
Parallel Vibration
Perpendicular Vibration
Direction of Energy
Direction of Energy
Amplitude = amount of energy Frequency = number of waves in
given time (Hz – 1 Hz=1 wave/sec)
Speed of wave Speed = freq x wavelength (λ)
Depends on medium its traveling in Density (moves slower) – more inertia Elasticity (faster) – faster in solid than liquid/gas temperature
Write these notes down…
Key Vocab for Wave interactions Reflection – bouncing back of a wave
after it strikes a boundary that does not absorb all the wave’s energy Ray is a line drawn to show direction of a wave
and show wave activity Incident – incoming wave Reflected wave – wave being bounced back
Refraction – bending of waves due to a change in speed (occurs because waves move at different speeds in different mediums) – air to water, glass to air
Diffraction – bending of waves around the edge of an obstacle
The amount of diffraction depends on the wave length and the size of obstacle
Snowball vs. yelling
Interference – When 2 or more waves arrive at the same place at the same time – they combine to form a single wave Constructive = combine (larger amplitude) Destructive = cancel (no wave)
What wave interaction is happening to the spoon in the water?
What type of wave interaction is this?
Car headlights with open eyes
Car headlights with squinted eyelashes
What type of wave interaction is this?
What type of wave interaction is this?
What type of wave interaction is this?
What type of wave interaction is this?
What type of wave interaction is this?
http://media.pearsoncmg.com/aw/aw_0media_physics/hewittvideos/doppler.html
As a table Summarize what the doppler effect is Be ready to share
Doppler Apparent change in pitch caused by
motion As moving towards me, pitch is
higher As moving away from me, pitch is
lower
Electromagnetic Spectrum
Wavelength and the Spectrum
Electromagnetic waves Produced by the movement of
electrically charged particles Can travel in a “vacuum” (they do
NOT need a medium Travel at the speed of
light Also known as EM waves
Radio waves Longest wavelength EM waves Uses:
TV broadcasting AM and FM broadcast radio Avalanche beacons Heart rate monitors Cell phone communication
Microwaves Wavelengths from 1 mm- 1 m Uses:
Microwave ovens Bluetooth headsets Broadband Wireless Internet Radar GPS
Infrared Radiation Wavelengths in between microwaves
and visible light Uses:
Night vision goggles Remote controls Heat-seeking missiles
Visible light Only type of EM wave able to be
detected by the human eye Violet is the highest frequency light Red light is the lowest frequency
light
Ultraviolet Shorter wavelengths than visible
light Uses:
Black lights Sterilizing medical equipment Water disinfection Security images on money
Ultraviolet (cont.)UVA UVB and UVC
Energy Highest of UV waves
Lower than UVA
Health risks
Extremely low risk for DNA damage Can destroy Vitamin A in skin
Can cause DNA damage, leading to skin cancer Responsible for sunburn
X-rays Tiny wavelength, high
energy waves Uses:
Medical imaging Airport security Inspecting industrial welds
Gamma Rays Smallest wavelengths, highest
energy EM waves Uses
Food irradiation Cancer treatment Treating wood flooring
Image credits1. http://www.antonine-education.co.uk/New_items/MUS/images/M
aking6.gif2. http://www.geocities.com/researchtriangle/campus/6791/einstei
n12.jpg3. http://abyss.uoregon.edu/~js/glossary/wave_particle.html4. http://www.astro.princeton.edu/~gk/A402/electromagnetic_spec
trum.jpg5. http://science.hq.nasa.gov/kids/imagers/ems/radio.html6. http://www.nentjes.info/Palace/radio-6.gif7. http://www.mobilewhack.com/motorola-h12-bluetooth-headset.j
pg8. http://www.stuffintheair.com/radar-real-time-weather.html9. http://www.imaging1.com/gallery/images/AV%20Night%20vision
%20goggles.jpg10. http://www.global-b2b-network.com/direct/dbimage/50329753/S
tudy_Remote_Control.jpg11. http://www.georgiaprismaward.com/The_Prism_Story_files/PRIS
M%20brand%20imagemed.jpg12. http://science.hq.nasa.gov/kids/imagers/ems/uv.html
Image Credits13. http://farm3.static.flickr.com/2385/2381723771_12548f4b
d1.jpg?v=121742987914. http://intamod.com.au/images/uv2.JPG15. http://science.hq.nasa.gov/kids/imagers/ems/xrays.html16. http://www.sciencelearn.org.nz/var/sciencelearn/storage/
images/contexts/see_through_body/sci_media/neck_x_ray/17945-5-eng-NZ/neck_x_ray_full_size_portrait.jpg
17. http://www.epinion.eu/wordpress/wp-content/uploads/2008/05/airport-security1.jpg
18. http://science.hq.nasa.gov/kids/imagers/ems/gamma.html19. http://www.aboutnuclear.org/print.cgi?fC=Food20. http://www.roswellpark.org/files/1_2_1/brain_spinal/
gamma%20knife%204c.jpg