All Sounds Are Created by Vibrations

Sound Notes:  All sounds are created by vibrations  A vibration is the complete back and forth motion of an object  Sound waves are longitudinal waves  All sound waves need a medium to travel through o Therefore all sound waves are mechanical waves  Recall Facts: o Does the medium travel with the wave? No

Properties of Sound  Recall: the speed is how fast a wave travels o The speed of sound depends on the medium in which the sound is traveling. . Sound travels fastest in Solids because the particles are close together . Sound travels second fastest in liquids because the particles are still close together but a little farther apart . Sound travels slowest in gases because the particles are far apart

 Pitch: how high or low something sounds o The pitch of a sound depends on the frequency of the sound wave.

o High frequency equals high pitch . More energy . Shorter wavelength

o Low frequency equals low pitch . Less energy . Longer wavelengths

 Loudness is a measure of how well a sound can be heard. o Loudness is related to the amplitude of a wave . The bigger the amplitude, the louder the sound  Louder the sound, the more energy the wave has . The smaller the amplitude, the softer the sound  Soft sound equals less energy Electromagnetic Waves Notes:  Electromagnetic waves are transverse waves that do not need a medium to travel through o This means they can travel in space  The transfer of energy as electromagnetic waves is called radiation  The arrangement of electromagnetic waves according to their wavelengths is called the Electromagnetic Spectrum  Remember: speed = wavelength x frequency o As the wavelength increases (gets longer), the frequency decreases (gets lower) o As the wavelength decreases (gets shorter), the frequency increases (gets higher)

 Waves with the longest wavelength have the lowest frequencies and the lowest energy  Waves with the shortest wavelengths have the highest frequencies and the highest energy

Radio Waves Microwaves -longest wavelengths -2nd longest wavelengths -lowest frequencies and energy -2nd lowest frequency and energy -examples: radio, tv, radar -examples: microwave ovens, cell phones

Infrared Visible light -heat waves -only EM wave we can see -3rd longest wavelengths -middle of the spectrum -3rd lowest frequency and energy -ROY G BIV (red, orange, yellow, green, -examples: tv remotes, heat lamps blue, indigo, violet) in order from the longest wavelength to the shortest (infrared is before red and ultraviolet is after violet!) Ultraviolet X-rays -3rd shortest wavelength -2nd shortest wavelengths -3rd highest frequency and energy -2nd highest frequencies and energy -too much can cause sun burn -can pass through skin but bot bone or -examples: black lights, sterilizers metal Gamma Rays -shortest wavelength -highest frequency and energy -most penetrating and dangerous of all the waves -examples: cancer treatment, cat scans, nuclear reactions

Light and Color Notes