Sound & Standing Waves Flashcards
What is sound
Vibrating particles
What are the two different sound waves
Longitudinal and mechanical
Speed of sound equation
V=f入
Uses of sound reflection and echo location
In ships to measure distance from objects and depth
Echo-sounding equation
Depth=speed x time/2
General properties of sound waves
- amplitude
- wavelength
- crest
- trough
Definition and uses of infrasound
Sound which is below the audible range
•track seismic activity
•elephants and giraffes use to communicate from far distances
•track the passage of meteors
Definition and uses of ultrasound
Sound above the audible range
•imaging(pregnancy scans)
•echosounding(sonar for maritime vessels)
•ultrasonic cleaning
What is power + formula + unit
The rate at which it converts electrical energy into other forms of energy
P= w/t = e/t
Unit is watt
Formula for electrical power
P=VI
power= voltage x current
P=I2R
How are sound waves displayed on the CRO oscilloscope
Sound waves(longitudinal waves) are displayed as transverse waves
how do sound waves appear with different characteristics
low frequency, low intensity-low waves(amp), long wavelength
high pitch, soft-low waves, short wavelength
low frequency, large intensity- long wavelength, high waves
high frequency, large intensity- short wavelengths, high waves
How is sound intensity measured
the decibel (dB)
Formation of standing waves through interferences
Two identical waves, traveling in opposite directions, pass through each other and combine. If the wavelength of the waves fits into the length available, a standing wave is formed.
What is a fundamental, frequency and harmonic
The 1st loop is called the fundamental or the 1st harmonic.
The second loop is the 2nd harmonic or overturn and so on.
(the number of string loops=number of harmonics)
frequency of the waves is the same as frequency of sound.
Number of loops is directly proportional to the frequency.
