Presentation on theme: "What are waves? Def. - Disturbances that carry energy from place to place, through matter or space."— Presentation transcript:
What are waves? Def. - Disturbances that carry energy from place to place, through matter or space.
Most waves begin with a vibration Waves are made when you speak And heard when you listen Waves can travel through space Waves can make the earth move and shake And make the light you see
A medium can be a: is the material in which a wave moves How dolphins communicate wood of a guitar Music from your radio to your ear
through medium doesnt move with the wave Energy moves through the medium. The medium just vibrates back and forth and doesnt move with the wave. The medium can move in two ways: 1. Transverse waves 2. Longitudinal waves
Medium moves at right angles to the direction of the wave. Ex) football stadium wave A) Crest: highest point B) Trough: lowest point
Crest Trough Amplitude Wavelength or Rest position
Medium moves parallel to the direction of the wave Ex. – a slinky or metal spring A) Compressions: where the molecules are crowded together B) Rarefactions: where the molecules spread apart. Made up of:
Sonograms: Ultrasonic waves (about 20,000 Hz) used to create images of fetuses in the womb Regular sonogram 3D sonogram
Supersonic: faster than the speed of sound. A US Navy F/A-18E/F Super Hornet in Transonic Flight Transonic: where only some parts of the air around an object (such as the ends of rotor blades) reach supersonic speeds (typically somewhere between Mach 0.8 and Mach 1.2).
An equal mixture of all frequencies of sound mage:Whitenoisesound.ogg
Change in pitch due to motion.
*moving towards increases the pitch *moving away decreases the pitch New word for the day: Dopeler Effect (n) The tendency of stupid ideas to seem smarter when they come at you rapidly.
Amount of energy measured in decibels (dB) Depends on the amplitude of sound waves. Large Amplitude = Loud sound Small Amplitude = Soft sound
Near total silence - 0 dB A whisper - 15 dB Normal conversation - 60 dB Lawnmower - 90 dB Threshold of pain dB A rock concert or a jet engine dB Gunshot, firecracker dB Near total silence - 0 dB A whisper - 15 dB Normal conversation - 60 dB Lawnmower - 90 dB Threshold of pain dB A rock concert or a jet engine dB Gunshot, firecracker dB Measurement of loudness
Displeasing sounds that disrupt the activity or happiness of human or animal life. Causes: –Damage to the ear –Stress –Hearing Loss A sound tube designed to decrease roadway noise