Understanding Beat Frequency: Equations and Solutions

[thereddevils]

Homework Statement

See attachment.

Homework Equations

The Attempt at a Solution

f1 - f2 = 5

What's there for me to interpret in the graph?

 

[Rick88]

From the graph you can see 8 complete wavelengths. This occurs in an interval of 0.15s

therefore f=number of events(or wavelengths) / $$\Delta$$t .


R.

 

[thereddevils]

From the graph you can see 8 complete wavelengths. This occurs in an interval of 0.15s

therefore f=number of events(or wavelengths) / $$\Delta$$t .


R.

I counted 7.5 and taking a closer look the interval is 0.16.

f=8/(0.16)=50

What is this frequency? Is it the frequency of one of the sources? Or is it the resultant frequency?

By the way, the answer given is A

 

[Redbelly98]

The f you calculated is the average of f1 and f2.

The Attempt at a Solution

f1 - f2 = 5

The answer choices suggest a different value for f1 - f2.

 

[thereddevils]

The f you calculated is the average of f1 and f2.

The answer choices suggest a different value for f1 - f2.

so the answer should be C?

 

[Redbelly98]

so the answer should be C?

Based on your calculation of 50 Hz, yes. However, I recommend doing the following calculation over (can you spot the error?):

I counted 7.5 and taking a closer look the interval is 0.16.

f=8/(0.16)=50

By the way, the answer given is A

I think the author of the question is confused. They also stated the wrong beat frequency in the problem statement.

 

[thereddevils]

Based on your calculation of 50 Hz, yes. However, I recommend doing the following calculation over (can you spot the error?):



I think the author of the question is confused. They also stated the wrong beat frequency in the problem statement.

ok thanks all for helping.