Question

Phys1011: Waves on a String and Frequencies of Tones and Voice The purpose of this lab is to examine properties of waves and become familiar with terms used in describing waves. Simulator questions are adapted from PhET contributors Trish Loeblein and Susie Dykstra. Part 1 – PhET Waves on a String simulator: Watch the lab video. Open Waves on a String (https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html). Investigate wave behavior using the simulation for a few minutes. For these lab exercises, set up the sim for a sine wave by selecting “No End” and adjusting “Damping” to “None”. Select ‘Oscillate. 2. Write a hypothesis about the relationship between a wave variable in the simulator and its effect on wave speed (amplitude, frequency, tension). Test your wave speed hypotheses, and determine the relationships between the wave variables and wave speed. Make claims about the relationships (direct, inverse, none) between wave variables, using evidence to support claims, and explaining the relationship between the claim and evidence. 3. Frequency and wavelength are both in your equation for speed. Why is it that, when you changed the frequency, you did not change the speed of the wave? 4. The only variable we found that affects the speed of a wave on a string was the tension of the string. How does this relate to how a musician tunes a stringed instrument? 5. How does increasing damping change the wave?

Answer 1

(1) (2) Okay, i did the simulation

I set the damping to none and string to no end. Here is what i observed

When i changed the amplitude, the speed of the wave remains somewhat same. When I increased the frequency, the speed of the wave remains same however i see more peaks of wave passing each second.

However, when i changed the tension, the speed increases with increase in tension and decreases with decrease in tension.

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(3) If speed is frequency times wavelength, then why doesn’t frequency affect speed?

This is because in a given medium, increasing the frequency decreases the wavelength and also the variables are inverse, so product would stay same

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(4) increasing the tension will speed up the wave and this will help to increase the pitch and will help in getting desired pitch.

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(5) as we increase the damping, there is no wave propagation at all, means the wave does not propagate, it oscillates at a single place.