Section 1 Flashcards
Explain the physical aspect of sound
The measured area of sound: frequency, intensity, spectrum. Ex: If a tree fell in the forest with nobody around, it would still make a sound.
What is the definition of sound
The movement of a disturbance (vibration) through an elastic medium (air)
What is equilibrium and how does it relate to sound?
The state of rest that undisturbed air remains in where molecules are evenly spaced
What is Brownian Motion/Movement
The rapid/random movement of air particles, which varies according to temperature and atmospheric pressure. Ex: A tea kettle heating molecules resulting in molecule movement/ the kettle whistling
What are the prerequisites for sound production?
- Medium to transmit sound
2. Source of energy
What must a medium have in order to transmit sound?
Must have mass/inertia and elasticity
What is Newton’s 2nd law of motion
An object in motion stays in motion- the more force, the more acceleration
How do elasticity, mass, inertia, resting force, equilibrium and friction/resistance all relate to sound?
An object or mass must be available to vibrate. Said mass must have elasticity in order to vibrate. Inertia shows how a mass wants to stay in equilibrium/ return to equilibrium via it’s restoring force but will continue to be in motion once disturbed. Friction and resistance will eventually force a mass to return to it’s resting state.
What is compression/condensation
When air molecules move closer together they become more dense and compressed than atmospheric pressure. ie: the upper portion of a wave
What is rarefaction?
When air molecules pull apart- leading to pressure that is less dense than surrounding air pressure. ie: the bottom part of a wave
What is a transverse wave? Does it occur in all mediums?
A wave where the molecular motion is perpendicular to the direction of a wave’s motion. It does not occur in liquids or gases as they do not support a shearing stress. Ex: water/cork bobbing on surface.
What is a longitudinal wave?
Displacement of the medium is parallel to propagation of the wave. Any matter that responds to compression with elasticity will transmit longitudinal waves.
What type of waves are sound waves?
Longitudinal
What is vibration as it relates to sound?
Motion back and forth along a path in such a manner that there is a restoring force (potential energy) increasing with displacement and always directed toward a position of rest.
What is restoring force?
Force that brings a vibrating object back to resting state
