Lab 10 Waves done (Fall 2021) (1)

Name: Lucero Puente INSTRUCTIONS: (1) Download this lab document and type out answers on the space provided for then save your answers. (2) If the spacing automatically moves, adjust so that your answers are not all over the place. (3) Upload this document, with your answers on it, on the designated Lab 10 Dropbox on Canvas Lab Reports/Module Tab. (4) If possible, ALL answers must be in green font or highlighted in yellow background with black font . Grading Policy for Lab Reports WITH Pre-/Post-lab Questions Grading Policy for Lab Reports WITHOUT Pre-/Post-lab Questions Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 70% 2. Pre-/Post-lab questions – 10% 3. Conclusions and real-life applications – 20% Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 80% 2. Conclusions & real-life applications – 20% This lab uses the Waves Intro simulation from PhET Interactive Simulations at University of Colorado Boulder, under the CC-BY 4.0 license. Purposes/Objectives: In this lab, you will be able to: 1) make or generate waves with water, sound, and light and find out how they are related. 2) differentiate transverse and longitudinal wave. 3) explain how changing the frequency and amplitude affects the characteristics of the wave. Definitions: Transverse wave are those waves that propagate or travel perpendicular or sideways or up-and- down to the direction of motion. Longitudinal wave are those waves that propagate or travel parallel or back and forth to the direction of motion. Frequency, f – the number of waves or cycles per second. Amplitude, A – the height of a wave from the equilibrium position to the crest (highest point of a transverse wave) or from the equilibrium position to the trough (lowest point of a transverse wave). Procedure: A. Develop your understanding: 1) Click the link below (hover mouse on the link then press at the same time: ctrl and left click ) https://phet.colorado.edu/sims/html/waves-intro/latest/waves-intro_en.html 2) Once Wave Intro PhET Sim opens, your screen should look like the one below. Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

3) Explore the Water, Sound, and Light screens or tabs . The circular orange button at the bottom right corner of each tab is the Reset button. What did you discover? Write your answers below. Also, paste below (inside the box space) screenshots to support your answers. Discovery: (1) Water waves – (2) Sound waves – (3) Light waves – 3 Screenshots, one for water , one for sound and one for light : (1) Screenshot for the water waves It seems that the waves are in constant pace, and it seems like the crests are more remarkable in the view than the troughs. And, making a comparison with the 3mediums, waves at water are the slowest. (2) Screenshot for the sound waves Same analysis as with the water waves. Moreover, every time that the throughs were made appeared as color black. Is when the sound was heard; and when the crest were made white, the sound temporality stop. And in comparison, with the other two of waves, the sound waves are the second fastest of the 3 Light Wave: Same analysis as with the other two. In here, the frequency seems a lot more than in the other two mediums even thought they all 3 have the same Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

8) Increase the amplitude, A by moving the Amplitude slider to the right. What happens with the (number of) waves? 9) Return the Frequency and Amplitude sliders to the middle. Now decrease the frequency, f by moving the Frequency slider to the left. a) What happens with the number of waves? b) What happens to the distance between waves (wavelength,  )? 10) Decrease the amplitude, A by moving the Amplitude slider to the left. What happens with the (number of) waves? As the frequency remains the same, the only modification on the waves is their amplitude. As the amplitude increases, the waves become taller. They went from an amplitude of almost 1cm to and amplitude of almost 2cm. The number of waves is the same as the previous question because the number is based on frequency, not amplitude. The waves are seem like in a “ slow-motion effect” asking waves less frequent. Therefore, the number of waves are less. The wavelength went from beign too short to be too long. This is because as the frequency reduces, the wavelength become wider As the amplitude also decreases, just like frequency, the waves disappear because the amplitude is reduced to 0 cm and the frequency is reduced to 0. Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

C. Expand your understanding: 11) Choose the Sound (Speaker symbol) tab from the bottom of the screen. Set to Side View and the Multiple Waves. Adjust Frequency and Amplitude in the middle (just like you did with the Water ). Choose Play Tone and Waves. 12) You can have your sound on - but don’t make it extremely loud. Push the green button for sound. What do you notice about the waves? 13) What do you notice about the speaker? 14) Is this a transverse or longitudinal wave? How do you know? 15) Now increase the frequency. How does the speaker movement change? The waves are in a constant pattern, having a higher amplitude and wavelength than the water waves. The sound made by the speaker is neither too loud nor too quite. It is in a middle ground of pitch sound, bearable to the human ear. Likewaise, the speaker zgoes back and forth when making the sound The sound waves are longitudinal waves. It vibrates compression and rarefaction through air The speaker movement increases; we see that the speaker goes back and forth more rapidly creating more waves. Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

b) What happens to the number of waves? c) What happens to the distance between waves (wavelength)? 19) Increase the amplitude. How does the speaker movement change? 20) Does the pitch change? 21) What happens to the volume? As the frequency reduces, the number or waves are also reduced. Less frequency, less waves The wavelength becomes wider waves longer than before. The speaker movement remains the same regarding velocity. Nevertheless, we can see that the speaker itself goes back and forth with more intensity. In other words, the speaker goes back deeply before returning No, the pitch remains the same pitch in link with frequency, not amplitude Just like the pitch, the sound volume remains the same with the tone pay on; but if it is off then we realized the vlume increases. Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

22) Decrease the amplitude. How does the speaker movement change? 23) Does the pitch change? 24) What happens to the volume? 25) Turn off (uncheck) the Play Tone. Click on Both (for particles and waves). Move the Frequency and Amplitude sliders side to side (high to low). Watch the particles, especially the red dots. 26) Describe how the particles move (wave energy). As we go reducing the amplitude the back and forth dimmish making the speaker movement reduced. And as the amplitude reached 0 the waves stope.. When the amplitude is at 0 the pitch is not gone. Yet, when the amplitude is closest to 0 but it not 0, the pitch remains the same as it was when the amplitude was higher When amplitude reaches 0, the volume of the speaker is now gone, just like the pitch It can be seen that the particles moved in a longitudinal wave. If we see close enough the red particles, we see that they moved as the crest goes and the trough to. And watching the big pictures, we see a compression and decompression of the particles. Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

30) Slide the frequency to the right (a higher frequency). a) What happens to the color? b) What happens to the number of waves? c) What happens to the distance between the waves (wavelength)? 31) Choose one color (frequency). Increase the Amplitude. a) Does the color (frequency) change? b) Does the brightness change? How? The color changes from a very dark red to a dark violet The number of waves increases as the frequency increases. The wave length becomes shorter The color chosen was sky blue. Now as we increase the amplitude, we notice that the color does not change. It remains the same as the amplitude increases Yes. As the amplitude increases it is very noticeable that the flashes of light are more intense and the light takes its time to fade away Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics

32) Choose one color (frequency). Decrease the Amplitude a) Does the color (frequency) change? b) Does the brightness change? How? Summary/Postlab Activity: Describe what you see (or hear) for each situation. The second and third columns are already filled out/answered for you. Wave/ Medium High Amplitude Low Amplitude High Frequency Low Frequency Short Wavelength Long Wavelength Water Tall waves Small waves More number of waves Less number of waves Means high frequency Means low frequency Sound Loud sound Soft sound Loud pitch Dim pitch Means high frequency Means low frequency Light Bright light Faint light Change of color to violet Change of color to red Means high frequency, violet Means low frequency, red The color remains sky blue as the amplitude decreases, the color does not change Yes, we can see that the flashes of light are less intense; the light is very opaque, and if fades away faster Conclusions: Write a summary (explanations) of the physics concepts learned based from the results of the lab experiment. Elaborate. Provide real-life applications/examples. As very clearly stated, the topic of the lab was waves. A wave is a wiggle in space and time that transport energy or signal. And there are three types of waves, water, sound, and light waves. Each and every type of wave share same composition; wavelength, frequency, crest, and trough. First, a Lab 10: Waves (Water, Sound & Light) © 2020 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics