# Shared Flashcard Set

## Details

Physics Ch. 7 - Waves and Sound
MCAT
19
Physics
05/31/2016

Term
 sinusoidal waves
Definition
 may be transverse or longitudinal; individual particles oscillate back and forth with a displacement that follows a sinusoidal pattern
Term
 transverse waves
Definition
 have oscillations of wave particles perpendicular to teh direction of wave propagation
Term
 longitudinal waves
Definition
 have oscillations of wave particles parallel to the direction of wave propagation
Term
 Define the following terms: wavelength frequency propagation speed period angular frequency amplitude displacement
Definition
 λ - the distance between two crests or two troughs (in m or other length unit) f - the number of cycles it makes per second (in Hz) multiply the wavelength by the frequency; in electromagnetic waves it will always be equal to the speed of light T - the number of secodns it takes to complete a cycle; inverse of frequency f = 1/T ω - another way of expressing frequency and is expressed in radians per second A - the magnitude of its maximal displacement x - refers to how far a point is from the equilibrium position
Term
 constructive interference
Definition
 occurs with two waves that are exactly in phase with each other; if they are not exactly in phase it is considered partial constructive interference
Term
 detructive interference
Definition
 occurs when waves are perfectly out of phase; if not perfectly out of phase it is called partial destructive interference
Term
 traveling waves
Definition
 have continuously shifting points of maximum and minimum displacement
Term
 standing waves
Definition
 produced by the constructive and destructive interference of two waves of the same frequency traveling in opposite directions in the same space
Term
 nodes vs antinodes
Definition
 point of no oscillation vs point of maximum oscillation
Term
 What range of frequencies can a healthy young adult generally hear?
Definition
 20 Hz to 20,000 Hz
Term
 resonance
Definition
 the increase in amplitude that occurs when a periodic force is applied at the natural (resonant) frequency of an object
Term
 damping
Definition
 a decrease in amplitude caused by an applied or nonconservative force
Term
 equation for the speed of sound
Definition
 v = √(B/ρ) v is the speed of sound in m/s  B is the bulk modulus in Pascals (kg·m-1·s-2) ρ is the density of the medium in kg/L (kg·m-3)
Term
 What is the speed of sound in air at 20C?
Definition
 343 m/s
Term
 Doppler effect and equation
Definition
 a shift in perceived frequency of a sound compared to the actual frequency of the emitted sound when the source of the sound and its detector are moving relative to one another   [image] The upper sign should be used if the observer or the source are moving toward the other. The lower sign should be used if moving away from the other.
Term
 How to determine loudness or volume of sound?
Definition
 it is related to intensity I = P/A I is intensity in W/m2 P is power in W or J/s A is area in m2
Term
 What is the equation for determing surface area of a sphere?
Definition
 4πr2
Term
 What equation relates the length of a standing wave to the length of a string or open pipe supporting it?
Definition
 λ = 2L/n λ is wavelenth in m L is the length of the open pipe or string in m n is the harmonic which can be a positive nonzero integer
Term
 What equation relates the wavelength of a standing wave and the length of a close pipe that supports it?
Definition
 λ = 4L/n  λ is wavelenth in m L is the length of the closed pipe in m n is the harmonic which can be odd integers
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