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Science Thursday, October 31 st (week 1). Day: 10hr 43min Rise-7:36 Set-6:20 Moon: waning crescent, 11% illuminated Objectives: I will describe how waves move energy. Warm Up!.
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ScienceThursday, October 31st (week 1) Day: 10hr 43min Rise-7:36 Set-6:20 Moon: waning crescent, 11% illuminated Objectives: I will describe how waves move energy.
Warm Up! Question: Give two examples of each type of wave including the medium that it uses to travel. Use your Discovery Ed activity.
Important Information Due Today: Bellwork Week 9 was due yesterday. Test of 76 and lower-meet me for lunch! Homework Tonight: Study some vocab! Upcoming Events: Quarter 2 has started!
What is a wave?* • Energy is transferred through a wave. • Mechanical waves- travel through a medium • Electromagnetic waves- do not need a medium to travel • Can you think of examples of each? • Which one does this picture represent? • Sound waves are mechanical because they need a medium to travel.
Brain Pop • http://www.brainpop.com/science/energy/waves/
What is sound?* • Sound begins with a vibration. • Sounds travel in waves through a medium.
Mechanical Waves* Transverse Waves • The motion of the medium is perpendicular to the motion of the wave • Up and Down Waves • Longitudinal Waves • The motion of the medium is parallel to the motion of the wave • Back and Forth Waves • **Sound Waves**
Longitudinal Waves* Compression • When waves are close together Rarefaction • When waves are far apart
Transverse Waves* • Crest- highest point on a wave • Amplitude- Volume of a wave (height of a wave) • As wave height increases, volume increases • Measured in Decibels • Trough- lowest point on a wave • Frequency- Pitch, high or low (length of a wave) • As wavelength increases, pitch decreases • Measured in Hertz
Amplitude versus Frequency Amplitude • Which one will have the higher volume? Frequency • Which one will have the higher pitch?
What can you hear? Decibels (dB): Volume • Normal Speech: 60dB • Library: 40dB • Close Whisper: 20dB • Jet Engine: 140dB • Loud Rock Music: 110dB • Subway Train: 100dB • Busy Street Traffic: 70dB • 120dB or above usually causes pain to the ear Hertz (Hz): Pitch • Young people can hear frequencies between 20-20,000 Hz • Dogs can hear frequencies that range from 67-45,000 Hz • As you age, your ability to hear high frequency sound decreases.
Diagram of a Transverse Wave* CREST AMPLITUDE TROUGH WAVELENGTH
Cool Waves! • http://paws.kettering.edu/~drussell/Demos/waves-intro/waves-intro.html • http://sunshine.chpc.utah.edu/labs/waves/wave_basics/waves.htm • http://paws.kettering.edu/~drussell/Demos/waves/wavemotion.html
United Streaming • http://player.discoveryeducation.com/index.cfm?guidAssetId=75244603-66D0-4066-9608-85B309BD65FC&blnFromSearch=1&productcode=US