Sound - Waves, periodic motion and displacement Flashcards
What is a medium?
A medium refers to any substance that lets waves pass through them.
What is sound?
Sound is an energy wave caused by disturbance in the material medium through which it travels.
How does sound travel?
Sound requires a medium to travel as only compressions and rarefactions produce sound. (Hence, sound cannot travel through space)
What is the equilibrium condition (in terms of sound)?
Equilibrium condition - When there is no sound/disturbance in the material medium
What is displacement? (in terms of sound)
- Displacement refers to the distance a particle in a medium moves from its equilibrium/rest/mean position
- If the particle moves to the right, it is a positive displacement, and if the particle moves to the left it is a negative displacement
- This positive or negative displacement creates a periodic movement or vibration in the mediumt
What is periodic motion?
Periodic motion refers to any movement which involves to and fro motion from the equilibrium position (negative and positive displacement). It is a type of motion which repeats itself after regular intervals.
What is an oscillation/cycle/period?
An oscillation/cycle/period refers to one cycle/occurrence of positive and negative displacement.
What are the two types of waves?
Longitudinal and Transverse waves
What are longitudinal waves?
Longitudinal waves are waves where the particles of the medium move parallel to the direction of wave motion. For example, sound waves.
What are transverse waves?
Transverse waves are waves where the particles of the medium move perpendicularly to the direction of wave motion. For example, light waves
In sound waves/longitudinal waves, how do we identify compression and rarefaction?
In a longitudinal wave/sound wave:
High density - compression
Low Density - rarefaction
