Driving force from buzzer for jacket of length L

[member 731016]

Homework Statement

Please see below

Relevant Equations

Please see below

For this problem,

How do we tell when the buzzer vibrates during the cycle to provide the driving force?

Many thanks!

 

[haruspex]

How do we tell when the buzzer vibrates during the cycle to provide the driving force?

It's an example of resonance. https://en.wikipedia.org/wiki/Resonance.
Because there are losses in the swinging cloth, it will always be a bit behind the source of vibration (phase lag). As a result, the impetus from the source is reinforcing.

 

[member 731016]

It's an example of resonance. https://en.wikipedia.org/wiki/Resonance.
Because there are losses in the swinging cloth, it will always be a bit behind the source of vibration (phase lag). As a result, the impetus from the source is reinforcing.

Thank you for your reply @haruspex !