Sylvia Seraj PHYS110 Having a %22Ball%22 with Uncertainties Lab Team 3 - Sylvia Seraj

Siena College - General Physics 110 Having a “Ball” with Uncertainties Lab NAME: Sylvia Seraj GROUP MEMBERS: Emily, AG, Lisa, Kahmini Learning Goals 1. In this lab, you will engage with the ideas of (1) uncertainties in measurements and experiments and (2) data analysis. Equipment: Video of experiment (see link below), a stopwatch and/or timer app. Video: https://www.youtube.com/watch?v=_iuXgpFPnX0 Watch the video of two people (Professor Finn’s children, Caitlin and James) tossing a ball back and forth. Measure the time it takes for the ball to travel from one person to the other and record these times, keeping track of which person is throwing. That is, make one list of times for when Caitlin is throwing the ball, and a separate list of times for when James is throwing the ball. You may use a stopwatch/timer app on your phone to measure the time. Record these times. Your instructors will share a Google Sheet with the class so that everyone can enter their data on their own: https://docs.google.com/spreadsheets/d/1w5NAfE0wE5oXMcoW907Y3yQ7AOil1j2erRAE soV6kZ0/edit?usp=sharing Your instructors will use the spreadsheet to calculate: ● The average time and standard deviation for the times recorded for each throw. ● The average time and standard deviation for the times recorded by each person. Purpose & Procedures ● Briefly summarize, in your own words, the objective(s) of your experiments. For this procedure and experiment we are measuring the time of how fast Caitlin and James are throwing the ball, in order to do so we used a stopwatch to track the time of the video and wrote down each time they each threw the ball. Just from my observation James was throwing the ball much faster than Caitlin. In the experiment we will measure the Occurrences vs Mean time of Timer and also measure the number of occurrences vs time of individual throws. ● Describe your experimental procedures in enough detail that another group could recreate your experiments exactly -- not just do experiments similar to yours. In your detailed procedures, specify precisely how others will know when you started/stopped the time measuring device. We are testing the difference in time intervals of how fast they toss the ball. When watching the video we would record as soon as Caitlin or James threw the ball and then stop when the other person catches the ball. As we did this we would record each time and how long it 1

Siena College - General Physics 110 Having a “Ball” with Uncertainties Lab took them to throw the ball and then compare them at the end when it comes to their deviations. With this experiment we couldn't measure this precisely, so the data is not 100% accurate. Scientific Ability Missing Inadequate Needs Improvement Adequate B1 Is able to identify the phenomenon to be investigated No phenomenon is mentioned. The description of the phenomenon to be investigated is confusing, or it is not the phenomena of interest. The description of the phenomenon is vague or incomplete. The phenomenon to be investigated is clearly stated. B2 Is able to design a reliable experiment that investigates the phenomenon The experiment does not investigate the phenomenon. The experiment may not yield any interesting patterns. Some important aspects of the phenomenon will not be observable. The experiment might yield interesting patterns relevant to the investigation of the phenomenon. Data Tables ● Record all of the data that only you collected in your experiments in neat, easy to understand tables with units included . ● Take into consideration the number of trials that your group thinks should be run. Scientific Ability Missing Inadequate Needs Improvement Adequate G4 Is able to record and represent data in a meaningful way Data are either absent or incomprehensible. Some important data are absent or incomprehensible. All important data are present, but recorded in a way that requires some effort to comprehend. All important data are present, organized, and recorded clearly. Caitlins Time Measurements 1 2 3 4 5 6 7 8 9 10 11 12 13 Mean STD 1.19 1.36 1.2 1.4 1.5 1.66 1.3 1.32 1.33 0.77 1.34 1.21 1.13 1.2854 0.2088 James Time Measurements 1 2 3 4 5 6 7 8 9 10 11 12 13 Mean STD 1.74 1.58 1.71 1.7 1.44 1.35 1.41 1.54 2.27 1.56 1.46 1.56 1.48 1.6000 0.2338 For this experiment I think you would need to do 3 tests, to obtain accuracy of the trials, and I think you would need James and Caitlin to throw the ball a certain way each time. SO that way all of your data is consistent. 2

Siena College - General Physics 110 Having a “Ball” with Uncertainties Lab graphseach. Scientific Ability Missing Inadequate Needs Improvement Adequate A11 Graph No graph is present. A graph is present, but the axes are not labeled. There is no scale on the axes. The data points are incorrectly connected to each other instead of using an appropriate trendline. The graph is present and the axes are labeled, but the axes do not correspond to the independent and dependent variable OR the scale is not accurate. The data points are not connected to each other, but there is no trendline either. The graph has correctly labeled axes, the independent variable is along the horizontal axis and the scale is accurate. The trendline is correct. Data Analysis 1. What patterns did you notice in the experiments you performed? Reference your data tables and graphs. Throwing the ball back and forth. James for a portion of the time would throw it differently and that would affect him and it would take longer for his time of flight. In order to have accurate data, James would have had to throw the ball the same way each time. 2. State the values for the average time and standard deviation for the time recorded by you for each person (Caitlin and James). Caitlin James Mean STD 1.2854 0.2088 3. Do your values above seem reasonably close or significantly different in comparison to the averages reported by the class as a whole? How do you know? Class Average When comparing the class averages to mine I noticed that they are very similar. For James it was around the same number, but for Caitlin the class average was significantly higher than my average for her. I think this happened because everyone did the experiment the same but also in different ways. But compared to our tables the numbers are relatively close. The data although consistent is still different. Caitlin Caitlin Mean 1.3970 0.2441 Std 0.4807 0.2539 James James Mean 1.5605 0.2415 Std 0.4616 N/A 4. Would you expect every throw to have the same time-of-flight? Would you expect every person in the room to measure the same time-of-flight on any given throw? 4 Mean STD 1.6000 0.2338

Siena College - General Physics 110 Having a “Ball” with Uncertainties Lab No, I would not expect every throw to be identical unless they were throwing the ball the exact same way each time, because there was a discrepancy with how the ball is thrown. You have no way of being sure that the time will be the same. 5. Is there a difference in asking what is the average time for the throws recorded by one student and what is the average time that all students record for one throw? If so, describe the difference(s). The biggest difference is because we will all do the experiment using different measures, some used a stopwatch, some used their phones to time. If you look at the numbers in the graphs a lot of students got different results. So when you go to compute the average for the experiment based on Me and then other students, they will inevitably be slightly different from each other. But if you do an overall average you could compare it to each students average to see how close they would be to each other. 6. Do Caitlin and James have the same average time for their throws? Would you expect them to? Explain your thinking. For the class average Caitlin and James have very very close averages. It is not identical but it is relatively close, whereas i did not predict that because james was not completely throwing the ball the same the entire amount of time and he was throwing the ball much faster than caitlin but at least .20 seconds. SO it is surprising the average is so close. For my average it was about 300 different, so it could be because she is slower but also it is not consistent with the classes average, so now i think by testing the experiment again we can get to the bottom of this. 7. Do Caitlin and James have the same standard deviation in their time for their throws? Would you expect them to? Explain your thinking. The STD was also very very close, which is confusing because like I said james was throwing it differently and he was throwing it faster so in my opinion he should have a higher number than caitlin but he doesn't. 8. Did all the people in your group get the same average time? Or a better way of asking this question would be, are your answers consistent with one another? Yes our answers are consistent with each other due to us all using the same timer, our averages matched. 9. What may have contributed to uncertainties in your measurements? Identify as many sources of experimental uncertainty as you can. 1. The way the ball is thrown 2. The timer being used 3. The ground being stood on 4. How high the ball is thrown 5. The pattern the ball is thrown 6. The amount of force the ball is being thrown with All of these are considerable reasons to mess with the variables of the experiment and cause severe uncertainty. The last one that I would add is that human error could also be one of them. 5