Hands-On Experiments: Measuring Speed of Light and Sound
School
Northern Virginia Community College**We aren't endorsed by this school
Course
PHY 101
Subject
Chemistry
Date
Dec 12, 2024
Pages
3
Uploaded by DrFog15369
Waves Name__________According to the material you have at home, please select only one lab from the following two options. Grading rubric:6pt for Consistent results (The speed calculated should be consistent with the officialvalue). 6pt for Organization (Neat report on paper showing all the calculations to find thespeed)2pt for correct units3pt for a picture included of your experiment3pt for a picture/scan of your paper with all the workOption 1 (20pts)Measuring the speed of light with a chocolate bar (or marshmallows) using the Microwave standing wave.1.Follow this video for the steps' description. https://youtu.be/kpB1wezpJeE2.Perform the experiment according to the video description.3.Take a picture of the chocolate bar with the ruler on top showing the distance between two nodes (Two adjacent melted spots). Include the picture here. [Picture]4.Take a piece of paper and write the distance between two nodes. Calculate the speed oflight including all the steps that lead to the final answer. Do not forget to include the units.1/3
5.Include here a picture /scan of your paper with the solution. [Scan/picture]6.If your results are far away from the actual speed of light value, give a reasonable explanation of what went wrong. [Explanation]Tips. The chocolate bar should be longer than 10 cm. If the chocolate bar is too short you will not be able to see two melted points. Make sure that the turntable of the microwave is off, or justtake it out from the microwave. Sometimes the frequency of the microwave is written on the back, if it is too difficult to find it, you may research for the brand. Usually all microwaves have the same frequency! Option 2 (20pts)Measuring the speed of sound in air using a laptop (or a phone), earbuds, and three toilet paper rolls (or two kitchen towels).Web site https://www.npl.co.uk/measurement-at-home/measuring-sound-using-toilet-rolls1.Follow this video for the steps' description https://www.youtube.com/watch?v=ihKYVqkajig2.Perform the experiment according to the video description.3.Take a picture of the equipment you used and in the picture show a ruler measuring the distance between the two marked moments of silence on the earbud cord. Include the picture here. [Picture]4.Take a paper page and write the value of this distance which corresponds to the wavelength.5.On the same paper, show all the steps and show all calculations to find the speed of sound. Do not forget to include the units in your final answer.2/3
6.Include here a scan/picture of your work on paper. [Scan/picture]7.If your results are far from the actual value of the speed of sound, repeat the experiment to improve it and give a reasonable explanation of what went wrong. [Explanation]Tips. You want to perform the experiment in a quiet room. If you have wireless earbuds you mayattach one to a thin string. While pulling one earbud out from the tunnel, go very slowly. Typically there will be two moments of silence, usually no more than two. Mark the location on the cable of these two moments. You can use a pencil to mark the two spots. You want to measure the distance between them: this is the wavelength, .𝝺3/3