Interference
What is Interference?
- The phenomenon that occurs when two waves meet while travelling along the same medium
- The interference of waves causes the medium to take on a shape that results from the net effect of the two individuals waves upon the particle of the medium
Important Terms
Superposition → Describes the nature and behaviour of matter and forces, when two waves meet they interact and overlap, the two waves pass through without being disturbed.
Constructive Interference → Two or more waves with the same frequency and phase, forms a new wave with different amplitude, the interference of two or more waves with the same phase and frequency, causing a lone amplitude, with an amplitude of the sum of both separate waves
Destructive Interference → Two or more waves that are also the same but one is inverted, each point crosses each other out equaling a straight line, the interference of two waves of equal frequency and opposite phase, causing their cancellation where the one with the negative displacement always concurs the positive displacement of the other
Node →A point on the wave that has a minimum amplitude (no movement), is a point along a standing wave where the wave has minimum amplitude, sound waves for example: a guitar or any stringed instrument; nodes are produced to form harmonics
In-Phase vs. Out-of-Phase
In-Phase
When in-phase waves are added, they undergo constructive interference. The resultant wave would be the sum of both waves.
When the two separate waves come in contact it creates a singular larger (double sized) amplitude. Which is known as the constructive interference
When in-phase waves are added, they undergo constructive interference. The resultant wave would be the sum of both waves.
When the two separate waves come in contact it creates a singular larger (double sized) amplitude. Which is known as the constructive interference
Out-of-Phase
When out-of-phase waves are added, they undergo destructive interference. It gets cancelled out, and the result is a wave with no wavelength or amplitude; it's just a straight line.
When two opposite waves colide, they diminish each other causing a lower amplitude. Which is known as the destructive interference
When out-of-phase waves are added, they undergo destructive interference. It gets cancelled out, and the result is a wave with no wavelength or amplitude; it's just a straight line.
When two opposite waves colide, they diminish each other causing a lower amplitude. Which is known as the destructive interference
Example
- Waves are at different places
- One is a little delayed before the other
- Thus, it's out of phase
Applications of Reflection