Newton s Laws Notes 1 This is a two week lab that is done in your assigned room in in basement of LD 2 Turning in your results cluded a This experiment requires a formal lab report b Collaborate with your partners on data collection analysis and writing c Turn in a single group report and make sure the names of all group members are in d Upload your report to Canvas pdf format by the deadline in the course calendar e Do not upload your analysis spreadsheets or raw data Copy and paste figures and other f There is a typical lab report format available with the other handouts for this course elements from your spreadsheet into your report as needed 3 We recommend doing the report as soon as possible after your lab rather than waiting until it is almost due If you have questions you will want to have plenty of time to talk to your TA 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 For this lab you will design and implement an experiment that measures the acceleration of a two mass system and then compare your results with your calculations based on Newton s laws You will measure the acceleration based upon the kinematics You should vary the mass system the cart mass and the hanging mass and run the experiment multiple times These are things you will do 1 You will use the motion detector to measure the position of the cart and calculate the meas ured acceleration 2 You will use the electronic balance to measure the masses cart w any added masses string and hanging mass i e paperclips This mass data will be used to calculate the theoreti cal acceleration 3 You will record data and transfer it to Excel for analysis Analysis will include but not be limited to comparing the measured and theoretical accelerations 4 Identify errors that can occur in your experiment 5 Minimize those errors What you will learn Please review the learning goals for the semester in lab in the handout from the first week 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 3 You will learn to distinguish between two types of errors that occur in data systematic errors and random 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 What goes in my lab notes and what about my report 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 as the setup for measuring accelera tion and what you did while recording data Did you try different setups or take multiple data sets for same setup If you store multiple files record what filenames correspond to what conditions The purpose of a report is to explain what you learned and how you learned it The sorts of things that belong here are A description of each step you did as part of the activities Any graphs to show to your results A clear explanation of how you analyzed your results Explain differences between calculated theory and the actual measured accelerations Your conclusions about any relevant and useful information you were able to extract from the data An analysis of the errors of the in your experiment including an explanation of how calculated average acceleration found the standard deviation and determined the standard error EQUIPMENT For this lab the following are available for use dynamics cart string pulley w clamp paper clips set of standard masses electronic balance wooden stop block and motion detector DOs DON Ts Don t break the equipment Make sure the cart masses do not go too fast Please do not Do consult with your Lab TA about the various techniques you want to consider as you Don t forget to record all the masses for each run cart w any added masses string and Do use your imagination and have fun drop the set of standardized masses design your particular experiment hanging mass i e paperclips Set Up For a sample set up attach the pulley at one of the edges of the table Assemble the cart string and hanging mass as illustrated below Next you will set up a motion detector positioned somewhere behind the cart to measure the veloci ty of the cart versus time You will need to spend some time on this experimenting to find the best location You should practice with multiple runs starting the motion detector and then releasing the cart system to make sure that your set up is able to accurately record the velocity of the cart as it acceler ates It needs to be able to record the velocity for the entire trip across the surface of the table ACTIVITY 1 Constant Cart Mass Variable Hanging Mass Use a few standard masses and add them to the cart e g two 250 gram masses Don t for get to record the total mass cart with the added masses and string Select a paperclip this is your hanging mass Don t forget to record its mass If the system does not move select a heavier paperclip or add an additional one Once the cart is able to move you are ready for your runs You should practice starting the motion detec tors releasing the cart then stopping the motion detector Make sure to do multiple runs for a given hanging mass How many You choose the more you do the better your data and thus the experiment Next increase the hanging mass by adding another paperclip Again don t forget to record the total hanging mass Again do multiple runs Repeat by adding another paperclip How many times should you increase the paperclips You choose the more you do the better your data Save your data for each run cart mass hanging mass velocity vs time data in Excel to make graphs do analysis etc Using what you have learned in lecture about kinematics free body diagrams and Newton s laws fully analyze this system For example one can easily obtain the kinematical accelera tion from the data see 1 D kinematics In addition from Newton s laws one can uncover the dynamical acceleration which is mostly a function of the masses and to a much lesser degree axle friction pulley and wheels