The Accelerometer in your Phone Part 1 Notes 1 This is a one week lab and can be done at home with an appropriate smartphone If no one in your group has one please let your instructor know we can give you a loaner The app you will be using is very easy and is availa ble for both iPhones and Android 2 Turning in your results included a This lab requires a summary not a formal report b Collaborate with your partners on data collection analysis and writing c Turn in a single group summary and make sure the names of all group members are d Upload your summary to Canvas pdf format by the deadline in the course calendar e Do not upload your spreadsheet Copy and paste figures and other elements from your f There is a description of what is needed in a lab summary available with the other spreadsheet into your summary as needed handouts for this course 3 We strongly recommend doing the lab early in the week rather than waiting until it is almost due If you need to ask your TA questions you will want to have plenty of time before the deadline No excuses 4 Getting help a Your lab TA can answer questions during the lab by email or by setting up a time to b You can also ask advice from lab partners and or other students meet Objectives of this lab These are things you will address in your report 1 You will learn to use the accelerometer in your phone to gather data and transfer it to Excel or another program for analysis 2 You will measure the value of the gravitational acceleration constant g 3 You will learn and practice analyzing data 4 You will identify the sources of noise in your experiment 5 You will try some methods to minimize the noise in your experiment These are things you will do form multiple runs 1 Using the app measure the acceleration versus time for your phone as it rests on a table Per 2 Export your data to a computer and analyze it with excel 3 Explain why the data looks like it does 4 Investigate if other pertinent data are buried or hidden in your velocity versus time data Dis cuss those that you identify What you will learn Please review the learning goals for the semester in lab in the Lab Overview docu ment look in the Syllabus Task on CN In addition this lab has several specific goals 1 You will practice keeping lab notes in a paper notebook computer file or other format 2 You will enhance the data analysis skills you learned previously by applying them to real data and random errors 3 You will learn to distinguish between two types of errors that occur in data systematic errors 4 You will enhance your understanding of how noise arises in data and how to account for that noise when interpreting experimental results 5 You will practice scientific communication skills by preparing graphs and writing a formal lab report Equipment A smartphone with an accelerometer1 and the app phyphox https phyphox org Note you can also use physics toolbox sensor suite https www vieyrasoftware net or similar apps but the instructions here are written for phyphox Any smooth level surface a table counter or uncarpeted floor will do Excel Numbers or similar software Word or other word processor to prepare your summary What goes in my lab notes and what about my summary The purpose of lab notes is to enable you or a colleague to reconstruct what was done and why They don t have to be neat in complete sentences etc but they do have to be useful In a case like this they should include things like what surface you put the phone on and what you did while recording data Did you try banging the table What happened to the acceleration If you store multiple files record what filenames correspond to what conditions A summary is less formal than a report and has less detail but the goal is still the same to explain what you learned and how you learned it The sorts of things that belong here are A rough description of what you did in each activity An example graph Your conclusions about how the x y and z axes correspond to the front back and sides How you understand the noise present in your acceleration measurements and what you did of your phone to try to minimize the noise 1 Pretty much all smartphones will work If you can play a game that involves tilting the phone your phone has one ACTIVITY 1 Get comfortable with the app If you have not downloaded phyphox now is the time to do it Open the app and choose Ac celeration without g Familiarize yourself with the controls The app is capable of recording acceleration on three axes vs time First play around with it Which axis is which on your phone You can figure this out by tilting your phone various ways to see which one makes gravity align with each direction 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 Next practice sending yourself the data You can email it to yourself in excel format xls Finally practice working with the data Open the file on your computer using Excel or Numbers etc Get to know the structure of the data and make a sample graph of acceleration vs time ACTIVITY 2 Measure a on the table Record some good data with the phone just sitting for a while at least a few seconds Send yourself several runs of different lengths up to a minute or two Now your job is to make sense of the data Here are some things you should do Open your data file in Excel You will have multiple columns ax ay az and a Create a new column that reproduces a from the others It is just the magnitude of a vector You will notice that just sitting on the surface the total acceleration your phone measures is approximately g This is because it is measuring the force on a tiny weight inside the phone and telling you what g is based on a calibration of that weight The data includes BOTH kinds of errors random errors noise in the data and systematic errors errors that are con stant not fluctuating Now to understand those types of noise make some graphs and do some statistics In Excel you should be able to calculate the average acceleration the standard deviation and the standard error of the mean for each run You can also calculate the error between your measured value and the standard value g 9 8 m s2 Repeat this a few more times for each of your runs ACTIVITY 3 your choice Consider the sources of noise Some could be in the sensor itself but others could be actual vibra tion in your …