Nature of SoundBy Group 3IV-St. Catherine
The speed of light in a vacuum is 299,792,458 meters per second or 186,000 miles per second (669,600,000 mph), which is roughly 870,000 times faster than the speed of sound.This means that light travelsfaster than sound.
CAN SOUND TRAVEL IN WATER?
IS THERE SOUND ON THE MOON?
the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other mediumit is an ENERGY
Any sound that you hear as a tone is made of regular, evenly spaced waves of air molecules.NOISETONE
How is sound produced?Vibration and particles of fluidSource of sound Vibrations in molecules in all directions ear eardrums
How is sound transmitted?Through vibrationsTravel in air, liquid, gasThey do not travel in vacuum and so they do not travel in SPACE!
Wavelengthspacing of the waves - the distance from the high point of one wave to the next one
Speed is not the same with frequencyFrequency refers to the number of vibrations that an individual particle makes per unit of time (how often)speed refers to the distance that the disturbance travels per unit of time (how fast)
Intensityamount of energy flowing per unit time over an areadepends on the amplitude and the distance of the observer from the source
Loudnesssubjective response that will vary with a number of factors.scale extending from 'soft' to 'loud.measure of the response of the ear to the sound
Sensation of a frequencyHigh pitch = High FrequencyLow pitch = Low Frequency
Speed of Sound Waves in Solids, Liquids and GasesSpeed in Solids > Speed in Liquids > Speed in Gases
Why? This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it
The Quality of SoundTIMBRE - Timbre is what makes a particular musical sound different from anotherMusical instruments
FACTORS AFFECTING WAVE SPEED
Properties of medium1.1 Elastic properties maintaining the objects shape (no deformation) when force is applied. - fastest in solids, then liquids and lastly in gases
1.2 Inertial properties tendency to be lethargic in its state of motion- includes mass and density- sound will travel more faster in a less dense material than in a more dense material.
2. Properties of air, temperature and humidity
Speed of sound waves at different temperaturesHigher Temperature = Faster sound waves
Lower Temperature = Slower sound waves
Why? :/At lower temperatures the air is denser and therefore harder to travel through
Speed of sound in air= 331 m/s (at 0C)
Speed of a sound waveSpeed of a sound wave refers to how fast the disturbance is passed from particle to particle.
v = 331 m/s + (0.6 m/s/C) * TIn Celsius (C)
Speed vs. Distance Directly proportional
As speed increases, the distance covered increases too.
Series 1Series 2Series 3
To resize chart data range, drag lower right corner of range.
Example:Determine the speed of sound on a cold winter day (T=3 degrees C).
Example:SOLUTION:given: Temperature = 3C
v = 331 m/s + 0.6 m/s/C * T = 331 m/s + 0.6m/s/c * 3C = 332.8 m/s
doubling of the wavelength results in a halving of the frequency; yet the wave speed is not changedSpeed = Wavelength * Frequency v = f
Unit: Hertz (Hz)ANOTHER EQUATION TO DETERMINE THE SPEED
EXAMPLE Playing middle C on the piano keyboard produces a sound with a frequency of 256 Hz. Assuming the speed of sound in air is 345 m/s, determine the wavelength of the sound corresponding to the note of middle C.
EXAMPLE Solution:Given: frequency = 256 Hzspeed of sound in air = 345 m/swavelength = ?speed = wavelength * frequencywavelength = speed/frequency = 345 m/s / 256 Hz = 1.348 m = 1.35 m
IMPORTANT USES OF SOUND
Important uses of SOUNDUltra Sound tests - diagnostic imaging techniques to create images of blood vessels, tissues and organs- Pregnant women -Aid detection of heart disease, tumors, gallstones, etc
STETHOSCOPE-HEAR THE INTERNAL SOUNDS OF BODY.
-AMPLIFIES THE SOUND INSIDE YOUR BODY.
In fluidsIn solids
Pressure-pulse or compression-type wave -Sound wave that travels in fluids (liquid, gases)
Transverse wave the sound wave that travels in solids.
The Doppler Effect named after a scientist, Christian Doppler.