Interference:Beatsby Lubin Li

A beat is heard if two slightly different frequencies are heard at the same time

It is a result of the amplitude increasing as well as decreasing as a function of time

The variation in the amplitude is what is known as the beat

This concept is important in real world situations

-The concept of beats can be witnessed when tuning musical instruments with a tuning fork.

-A tuning fork can be struck with a rubber hammer to produce the frequency that resembles the “A” note (the frequency most tuning forks are made to ring) of an instrument like a piano.

-If you then play an out of tune “A” note on the instrument you will hear a slightly different frequency.

-This difference in frequency will cause a “beating” sound that is heard by our ear.

To successfully tune the instrument, or piano in our case, we need to adjust the strings that are connected to the keys.

We tighten or loosen the strings accordingly.

We continue to adjust the string which also adjusts the frequency expressed by the note until both the tuning fork frequency and the note frequency are the exact same.

We know that the frequencies are the same when our ears stop experiencing the “beating”.

Once both frequencies are in phase the “beating” stops.

Once the “A” note is in tune you can then adjust the other notes of the piano accordingly.

Tuning instruments is an application of Interference in the form of beats.

Thanks!