Acceleration Due to Gravity Vertical Direction Phyphox Lab Report

Acceleration Due to Gravity Vertical Direction Phyphox Lab Report

 
PHYS 15200 Mechanics                                                      



The Accelerometer in your Phone



Notes:



1.   This lab can be done anywhere, as long as you have an appropriate smartphone.



2.   You may work with your lab group or alone. You may turn in a single lab report for the group, and all authors listed will earn the same grade. If you prefer, you are always welcome to turn in your own lab report.



3.   Lab reports should be uploaded to Canvas by the deadline in the course calendar.



4.   I strongly recommend doing the lab early in the week, rather than waiting until it is almost due. If you have computer trouble, you will want to have plenty of time to fix it before the deadline. No excuses!



5.   The app you will be using is very easy and is available for both iPhones and An- droid. If you have any trouble, seek help from one another on CN.



6.   Your lab TA can answer questions by email and will be available via Zoom to help during the time indicated in the syllabus.



OBJECTIVE



In this experiment, you will explore the workings of the accelerometer embedded in your smartphone. It is a good opportunity to explore how data gathering with a “real” instrument works, and you’ll use this tool to do another experiment soon.



EQUIPMENT



A smartphone with an accelerometer1  and one of these apps:



•   phyphox https://phyphox.org/. (I think this one is a bit easier to use)



•   physics toolbox sensor suite. https://www.vieyrasoftware.net/



Any smooth surface: a table, counter, or room with a solid floor (carpet is not a good choice)



Excel, Numbers, or other graphing software



Word or other word processor to prepare your report



Background



Newton’s second law should be “second nature” to you by now:



??⃗  = ????⃗.



Your phone includes an accelerometer that measures the force on a known mass and calculates the acceleration of the phone. For details, check out https://www.engadget.com/2012-05-22-the-engineer- guy-shows-how-a-smartphone-accelerometer-works.html or other articles online. In this experiment, you are going to use this device.



1  Pretty much all smartphones will work. If you can play a game that involves tilting the phone, your phone has one.



The Accelerometer in your Phone



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PHYS 15200 Mechanics                                                     



PROCEDURE



PART I – What is g in your location?



1.  If you have not downloaded one of the apps above, now is the time to do it! Open the app and choose “acceleration with g” (phyphox) or “g-Force meter” (physics toolbox).



2.  Familiarize yourself with the controls. Both apps are capable of recording acceleration on three axes vs time. First play around with it. Which axis is which on your phone?



3.  Next, practice sending yourself the data. You can email it to yourself. The format is either .xls



(phyphox) or .csv (sensor kinetics) either way, excel can open it.



4.  Now, take some data. Just put your phone on a solid surface, turn on the accelerometer see what happens. Try tapping on the surface near the phone. Try jumping. What do you see?



5.  Clear the data, and record with the phone just sitting for a while (10 sec? 20?), stop it and send yourself the data.



6.  Now, your job is to make sense of the data. Here are some things you should do.



7.  Open your data file in Excel. You will have multiple columns. ax, ay, az, and |a|. You should be able to create a new column that reproduces |a| from the others. It is just the magnitude of a vec- tor! Show how you do this in your report.



8.  Make some graphs, do some statistics! According to your data, what is the average acceleration?



What is the uncertainty in your measurement? Explain how you found these values in your re- port.



9.  Your phone was just sitting there. Why is there any acceleration at all? Was your average 10? 1?



0.001? What are the units? Explain why it isn’t zero, and why it is whatever you measured. A



reader should be able to understand how to use this tool from your report.



10.Again, the phone was just resting. Why is the acceleration not constant with time? Explain pos- sible sources of the variation.



11.Test your explanations in the last two questions by doing more experiments? Doing them more carefully? Using a different surface? A different phone? Do at least one additional experiment to test your reasoning.



Summary



In the end, your report should include careful descriptions of the experiments you did, and how you made sense of the data. Include any graphs, tables, pictures or other information necessary for your reader to understand what you did and what you learned.



The Accelerometer in your Phone



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