Waves & Sound

• A wave is made up of periodic motion
• Vibration is also called oscillation
• Electromagnetic wave: are types of wave that can without medium travel

  Mechanical waves: are types of waves that cannot without medium travel
• Longitudinal waves: direction of vibration to the propagation is parallel

  Transverse wave: direction of vibration to the propagation is perpendicular
• Oscillation (vibration) is a motion repeated at regular intervals (periodic motion).
• Equilibrium: a point where an object experiences zero net
• Amplitude: maximum displacement of an object from its equilibrium position
• Period(T): Time taken for one complete vibration
• Frequency(f):The number of complete vibration in one second
• Wavelength(λ) = the length of 1 wave
• Speed of wave (v): distance of speed
• Period: T= t/n
• Frequency: f= 1/T
• Wavelength(λ) = v= λ/f
• Sound has amplitude, frequency, and wavelength
• Sound can go through solid, liquid, and gas
• The sound waves are carried by particles > the vibration is transferred from one particle to another > each particle vibrates back and forth > the sound waves reaches our ear
• Audible: means "able to be hard". human range is 20Hz to 20000Hz
• Infrasound: frequency below 20Hz
• Ultrasound: frequency above 20000Hz
• The speed of sound in the air is approximately 340m/s at 20C depending on the temp of the air
• Speed of sound: v= d/t
• Echo: v= 2d/t
• Echolocation: the use of sound to determine the location of objects
• Animals that use echolocation: Bats, whales, dolphins