Lesson 35
WAVES, SUPERPOSITION, AND INTERFERENCE
Name: etp       Section: M1       Start Time: 15:29:49       Instructor: Dr Evelyn E_Patterson       Course: 110H      


1) A certain transverse traveling wave on a string can be represented by the following equation



where y is the displacement of the string, x is position of a point along the string, and t is the time.

What are the units of the coefficients of the x-term and the t-term in the above expression? What do we call those coefficients?



2) Be sure the simulation has finished loading before you begin.

The next two questions pertain to the simulation below.

Test your function for g(x,t) here. g(x,t)=

Consider the wave f(x,t) in the top panel of the simulation. What are its (i) amplitude, (ii) wavelength, (iii) frequency, (iv) wavenumber, and (v) speed? Please briefly explain how you arrive at your answer (what you measured, counted, etc.) (Simulation Hints! Click the "Forward" button to run the simulation. The controls at the bottom work like VCR controls. You can click and drag inside the animation to read the coordinates in order to obtain numerical values for use in your equations. A running time display is in the top left corner of the top panel. Also note that you may want to stop the animation in order to measure things like the wavelength.)





3) This question refers to the Physlet that appears as part of the previous question.

What wave function, g(x,t) (middle panel), when added to f(x,t) (top panel), will produce a beat wave with a beat frequency of 0.2 Hz? Note that the superposition of f(x,t) and g(x,t) will appear in the bottom panel. Experiment with various functions for g(x,t) by entering your function in the small textarea immediately below the simulation and then clicking the "Enter" button next to the textarea. If you aren't sure how to answer this question, please explain what you do know about producing beats. Also, feel free to "play" with changing different parameters in the equation for g(x,t) to help you understand what each parameter affects or represents.





Below is a space for your thoughts, including general comments about today's assignment (what seemed impossible, what reading didn't make sense, what we should spend class time on, what was "cool", etc.):

You may change your mind as often as you wish. When you are satisfied with your responses click the SUBMIT button.

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I received help from someone on this assignment (document in comments section).