{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# act16ans - Do NOT write on these sheets or take them with...

This preview shows pages 1–3. Sign up to view the full content.

Do NOT write on these sheets or take them with you! The next class needs them too! PHYS-1200 PHYSICS II SPRING 2006 Class 16 Activity: Beats and the Doppler Effect SOLUTIONS Beats In this part of the activity you will study the phenomenon of beats using an Excel spreadsheet. The spreadsheet is already programmed to plot the sum of two sinusoidal waves of different frequencies. You will be able to change the frequencies and amplitudes of each of the waves, and observe the results. A picture of the spreadsheet is provided below. The frequencies of the two signals are entered in cells B4 and B5, and the amplitudes in cells B7 and B8. everything else is calculated and graphed automatically. A link to the spreadsheet is provided at the Physics II website, under “Class activities”. The graph of x 1 + x 2 as a function of time clearly shows the variation of amplitude known as beats. Open the program and follow the instructions below. 1. With f 1 = 350 Hz and f 2 = 375 Hz, and both A 1 and A 2 equal to one, measure the length of time that one beat lasts; in other words, the period of one beat ( T beat ). Then take the reciprocal of the period (1/ T beat ) to find the beat frequency. Record the results on your paper in the form shown below. T beat = 0.06 s – 0.02 s = 0.04 s f beat = 25 Hz units units Does the beat frequency seem to equal the frequency difference between the component signals? (Indicate YES or NO.) Turn the paper over. There is more on the back.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Do NOT write on these sheets or take them with you!
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}