Lab3_butomo

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Jan 9, 2024

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PHYS 172 LAB 03 Lab Orientation: Using iOLab Position Update: Displacement, Velocity, and Acceleration SPRING 2021 LAST NAME (ALL CAPS): __UTOMO_____________ FIRST NAME (ALL CAPS) ____BRAMANTIO________ PUID:___0032539685_ LAB Section DAY _WED___ LAB Section TIME __3:30-5:20___ LAB GROUP#__6_ (Asynchronous Students: for DAY and TIME, please type DIST) Learning Goals After completing this activity, you should be able to: • familiarize with the iOLab equipment; • understand the relationship between displacement, velocity, and acceleration; • use the position update method; • make a connection between the physical experiment and a VPython model. Equipment For this lab you need: the iOLab kit, computer with the USB port, and the internet connection. BEFORE YOU GO ANY FURTHER … Please read the instructions in LAB DATA SHARING on Brightspace (left panel) and complete steps 1-4 . Part 1: iOLab Basics Open up your iOLab kit. It should contain the iOLab cart and its accessories (screws, springs, and bolts). Carefully follow the steps described at Macmillan Learning for getting started with iOLab. Make sure you read the instructions for Preparing iOLab and Calibrating iOLab provided therein. Q1. At step “Record Data”, r ecord any measurement you want using iOLab. For example, select the Accelerometer sensor, then press ‘Record’, move the iOLab cart, and press ‘Stop’. You should see a graph (in our example - of acceleration vs time) plotted for you. Take a screenshot showing your iOLab graph(s) and paste it below.

Page 2 of 6 Strictly speaking, you cannot plot a graph from a single measurement. You need a lot of measurements for a single recording. Each quantity measured by an iOLab sensor has a particular frequency of measurements . It shows how fast the sensor performs those measurements. The units of frequency are Hertz (Hz). For example, if you record data for 2 s and obtain 1,000 measurements in the process, then the frequency of your measurements is 500 Hz (i.e. 500 measurements per second). You can see that number near the corresponding sensor name. Q2. In your recording for Q1, what was the frequency of measurements? What does that number mean with regards to your measurement (describe in your own words)? The frequency of the my measurement is 800 Hz. It means that IO Lab measurement collects the 800 data per second. Q3. Do you think, the number of Hz you read in Q2 represents any limitation to take into account when you are measuring using the iOLab? Explain your response. The number of Hz represents the limitation of the number of data that IO lab can measure or take within one second. In the example above, it could measure more than 800 data each second. Q4. Did you also read how to View Data and Share Data (yes/no)? Make sure you have successfully shared your data with your group (see below). Yes we have successfully shared our data. SHARE YOUR DATA WITH YOUR GROUP MEMBERS. SEE LAB DATA SHARING Instructions provided on Brightspace . Go to Content (top menu) > LAB Data Sharing (side bar)

Page 3 of 6 Part 2: Push Cart Experiment Set up the iOLab cart on a flat surface, such as the top of the table, and interface it with the computer. Set up the cart such that the direction of the axis 𝑦 is pointing to your right. • Insert the USB that comes with iOLab into the computer. Turn on the iOLab cart, and also open the iOLab application on the computer. • Select the ‘Wheel’ sensor. • Start the recording, give a gentle push to the iOLab cart, and after a little while stop the recording. You must be able to observe the position, velocity, and acceleration graphs. • Look carefully at the velocity graph. Focus on the section where the velocity is approximately constant. Note: If it is difficult to decide which part of the velocity graph is constant, try to zoom the graph using the tools You can see the graph curve in more details and should be able to decide which portion of the graph is approximately constant. The picture below shows the same graph before and after zooming it in. Look at the scales of the axes to get an idea of the amount of zooming done. Once you find the graph section where the velocity is approximately constant, note that value of the velocity (you can find the mean value of the velocity on a given segment using the tool ). Then for the same interval of time, focus on the position graph, and note the position at the beginning of that interval.

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Page 4 of 6 Q5. Enter the interval of time for the segment of the graph you chose, enter the value of the constant velocity in that interval of time, and enter the value of the position at the beginning of that interval. TAKE A SCREEN CAPTURE OF THE RELEVANT PORTION OF THE VELOCITY GRAPH AND PASTE IT BELOW TAKE A SCREEN CAPTURE OF THE RELEVANT PORTION OF THE POSITION GRAPH AND PASTE IT BELOW SHARE YOUR DATA WITH YOUR GROUP MEMBERS. SEE LAB DATA SHARING Instructions provided on Brightspace . Go to Content (top menu) > LAB Data Sharing (side bar) Q6. Based on the information in Q5, use the position update principle to predict the position at the end of the time interval that you selected. Time interval 1.32s – 1.47s. Using the position update principle where ry = ri + Vavg*deltaT, which means ry = 0.282m + 0.15s*0.240m/s which equals to 0.318m. Q7. From the position graph, note the position at the end of the time interval. How does this compare with the position you predicted above (from Q6)? The position on the graph shows that ry = 0.318 m. Is the same with what I have predicted above. Q8. Discuss with your team what must be the characteristics/criteria for a segment of the velocity graph to be considered constant-velocity. What was the agreement/disagreement in Q8 (Discussion)? The velocity graph should have a slope close to zero (horizontal) to be considered constant-velocity. The position graph should have a constant slope.

Page 5 of 6 Part 3: Connecting the Simulation with the Experiment With the data you have collected using the iOLab equipment it is possible to modify the computational model you analyzed in Lab 02 (PushCartSimulation) so that you can model the physical experiment from Part 2. • Take your code from the push cart program and copy it into a new file in your Public folder (call it “PushCartSimulation2”). • Adjust the numerical values (velocity, delta T, initial time, initial position, etc.) in the code to model the physical experiment done with the iOLab cart, during the time interval where we assumed the cart had constant velocity. Take a screen capture of the graphs (position and velocity vs time) you got from the VPython model and paste it below. • Compare the graphs obtained using iOLab with the ones obtained with the new model in VPython. Q09: How do the two graphs -- VPython model and iOLab experiment – differ from each other? The graph had different scale, but it shows similar result. The time vs velocity graph is a straight line in VPython model but in iOLab it has slight variations. The time and position is very similar they both have a constant slope. Q10: What assumptions about the cart system does the computational model make? Are these valid assumptions? Discuss with your team. The assumptions that the computational system made is that the cart velocity is always constant and there is no friction. These assumptions is valid for this experiment since the cart in VPhyton travelled the same amount of distance as the one in iOLab. Q11: How do these assumptions affect the accuracy of our results? For the push cart simulation, are the errors in the results due to these assumptions negligible? Why or why not? These assumptions could increase our experiment results. But for the push cart, the results due to these assumptions are neglible. This is because the distance that the cart travelled is the same with the one in iOLab. • Share the link to your finished program. To share your programs, navigate to your Public folder tab, copy the URL from the browser bar below: https://www.glowscript.org/#/user/utomo.bar/folder/Lab3/

Page 6 of 6 LAB Group Members’ Signatures /Typed Names (Make sure all agree to “sign off” on work) Jake Holliday Bram Utomo Caden Cunningham Angelica Jovceski Jaime Rueda BEFORE LEAVING, EACH PERSON IN GROUP MUST • Get signatures/typed names of every LAB Group member in the boxes on the left OR type in their name. • If you have printed it off, take photos of each page, and combine them into a single PDF. If you have been working in the Word file as is, then simply save it as PDF. Each person MUST upload THE SINGLE PDF File your LAB worksheet on Brightspace by 11:59 PM SATURDAY See Syllabus for LATE POLICY ASYNCHRONOUS STUDENTS: Please paste your entire Discussion Board here (or a link to Discussion video here)

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