I did this lab experiment and this was the feedback I got The point of this lab was to analyze the relationships as found in the formula for centripetal force.

This lab is notorious for high percent error in the hands-on part, especially if you are trying to do it on your own. This is why the simulation part is included.

In your first Data Table, I see an error with your calculation of Fg. Fg should equal the mass of the hanging mass (.03 kg) times 9.81 m/s^2, which does not equal 1.07 N. (-10 points) I also calculated the Fc using your work in the first trial, and I did not get 2.09 N. (-10 points ) I can see from the following data tables that you had incorrect calculations, because when using the simulator you should be getting percent errors below 10%. (usually below 5%) (-20 points)

Lab Experiment: Centripetal Acceleration Title: Centripetal Acceleration Purpose: To determine how varying the length of the radius of a rotating mass will affect the period (T). Procedure: Record the number of washers in data table 1. Calculate the average mass of each washer in data table 1. Weigh the rubber stopper and record its mass in data table 1. Assemble the centripetal apparatus. Swing the apparatus with the stopper on the top, while releasing the string slowly. Measure the radius of the spin circle in data table 2 as trial 1. Use a stopwatch to time 10 revolutions. Shorten the length of the string and the stopper and the top of the tube by 100m. Record the new radius as trial 2. . Repeat steps 6-10 for 2 more trials. . Do the calculations and record in data table 2. HHMDOOqchh-thrt pL [\\J . Open the online simulation. . Confirm the radius is set at 200 cm and the moving mass is set at 25 g. . Record the circumference and mass of the hanging washers in data table 3. . Press start and count 10 revs. . Record the time. . Do the calulations and record in data table 3. . Repeat steps 14-17 for data table 4, with adding washers. . Repeat steps 14-17 in data table 5 for the change in raii. . Cleanup isiIiIH Chm13w iIiL 00a] NiI OKD DATA Data table 1 Number of washers 20 Mass of the washers (kg) .11 Av mass of washer single (kg) 006 Rotating mass (kg) 017 Hanging mass (kg) 03 Data table 2 Radius Time - Time T Circumference Velocity | Fc (N) F: (N) % (m) 10 rev 1 rev (m) (m/s) Error (S (s .18 3.30 33 1.13 3.42 2.09 1.07 209.0 55 4.54 45 3.42 7.67 4.68 1.07 468 .30 4.11 41 1.82 4.59 2.80 1.0' 280 .25 4.05 .40 1.57 3.92 2.39 1.07 239 Exercise 2 Data table 3 Rotating mass (Kg) .025 Radius (m) 2.00 Circumference (m) 12.75 Trial Hanging Time - 10 Time T - Velocity Fc (N) F: (N) % Error Mass rev (S) 1 rev (s) (m/s) (kg) 1 10 13.9 1.39 9.04 45 86 54.02 2 15 11.5 1.15 10.90 54 1.47 44.80 3 .17 10.8 1.08 11.63 58 1.66 40.77 4 .2 9.9 99 12.69 63 2.05 35.67Data table 4 hanging mass (Kg) 025 Radius (m) 2.00 Circumference (m) 12.75 Trial rotating Time - 10 Time T - Velocity Fc (N) F: (N) % Error Mass rev (s) 1 rev (s) (m/s) (kg) 12 12.8 1.28 9.81 49 1.17 49.9 2 54 19.1 1.91 6.57 .32 5.29 67.27 3 84 23.8 2.38 5.27 26 8.23 73.39 4 1.17 28.3 2.83 4.44 .22 11.46 77.47 Data table 5 Rotating mass 025 (Kg Hanging mass .12 (kg) Trial Radius Time - Circumference Velocity Fo Fg % (m) 10 rev Time T - (m) (m/s) (N) (N) Error (s) 1 rev (s) 2 12.9 1.29 12.57 9.74 48 2.45 50.96 2 .4 5.5 55 2.51 4.56 .28 2.45 71.35 3 55 7.0 . 70 3.4 4.93 .24 2.45 75.43 .75 8.0 80 4.71 5.89 .29 2.45 70.33Exercise 1 - Questions Question 1 1. What effect does radius have on the velocity of a rotating object? 14 Word(s) As the radius of the object in motion increases, the velocity increases as well. Question 2 2. What effect does the velocity of a rotating object have on the centripetal force exerted on it? 21 Word(s) the bigger the velocity, the bigger the centripetal force is. if the speed is increasesd, a larger force will be needed. Question 3 3. The Moon orbits Earth at an average distance of 3.84 x 108 min a path that takes 27.3 days to complete. What is the centripetal acceleration of the Moon? (Remember, you must convert time into seconds.) 4 Word(s) 2.7 x 10'3 m/s2 Question 4 4. When a bucket of water is swung in a vertical circle, the water will remain in the bucket if the velocity is high enough. If you let the bucket slow down too much, the water will spill out. The critical velocity is the slowest velocity necessari to keep the water in the bucket. What is the critical velocity if the formula is velocity = , where r is the radius (the radius of your arm swing including the bucket) and g is the acceleration of gravity (g=9.81 m/sz)? Hint: You must measure or estimate the length from your shoulder to the center of the bucket to determine the radius. 1 Word(s) 2.9m/s Exercise 2 - Questions Question 1 1. What was the effect of increasing the hanging mass on the centripetal force in Part 1 of this exercise? 44 Word(s) as the hanging mass increased, the centripetal force increased. this can be seen in trial 1 with the smallest hanging mass of .lOkg and a centripetal force of .45N, then with the largest hanging mass of .21kg, there was a centripetal force of 12.69N. Question 2 2. Did increasing the mass of the rotating object affect its velocity in Part 2 of this exercise? Explain your answer by referencing Data Table 5. 52 Word(s) increasing the mass did in fact effect the velocity. as the mass increased, the velocity increased. for example, the mass of trial 1 was .12kg, and the velocity of trial 1 was the highest at 9.81m/s. then, trial 4 had the largest rotating mass of 1.17kg, with the smallest velocity of 4.44m/s. Question 3 3. What effect did increasing the radius of the rotating mass have on its velocity? Reference Data Table 6 in your answer. How do these results compare to those recorded in Exercise 1? 24 Word(s) increasing the radius slowed down the stopper, creating less velocity, becuase the gravitational force pulling it inward is weaker when it is farther away. Question 4 4. What factors introduced error in both Exercise 1 and Exercise 2? How could the error have been reduced? 46 Word(s) in both exercises, error was possible since the numbers of the time of the 10 revolutions could vary, depending on where each person decided to stop the clock. this could have been reduced with a way to stop the revolution in the same place each time. Question 5 5. How did using the simulations in Exercise 2 contribute to your understanding of centripetal acceleration? Did you nd them more or less effective than the physical experiment in Exercise 1? Explain your answer. 43 Word(s) i found this to be way more effective. with the hands on lab, it is easy to make mistakes that throw off the numbers, thus confusing the student even more. this online lab helped e understand the trends in the numbers even better. Results: The purpose of this lab was to determine how varying the length of the radius of a rotating mass will affect the period (T). The rst exercise in this lab was hands on. The second part was using an online simulator of the process that was done physically in the rst part. Overall, there are many trends that can be seen in this lab. For example, when the hanging mass increases, the time it takes for the stopper to make a full revolution decreases, however the velocity increases. Data table 3 proves this by showing that the smallest hanging mass of .10kg has the highest revolution time of 1.395 and a velocity of 9.04m/s. Then, the highest hanging mass of .21kg has a time of .995 and a velocity of 12.69m/s. Another trend can be seen in data table 4, whereas the rotating mass increases, the velocity decreases. For example, the smallest rotating mass is .12kg, and that had a velocity of 9.8 lm/s. Then, the largest rotating mass of l. 17kg had a velocity of 4.44m/s. nally, data table 5 shows that as the radius of the circle closes in and gets smaller, the velocity decreases. The biggest radius of 2m had the highest velocity of 9.74m/s while the smaller velocity of 4.56 was linked to the smallest radius of .4m. The rst part of this lab leaves a lot of room for error. Since it is done by a person who makes mistakes, there is a higher chance that the numbers could be off. Rather than the computer-generated lab which is always correct. Conclusion: This experiment showed me the trends of centripetal acceleration a lot more clearly. Especially in exercise two that was done online, I was able to really see how it worked, while getting numbers that were correct and made sense. I believe I had some mistakes in part one which conlsed me since I redid it again and got similar mistakes. However, after completing the second part, the ideas became a lot clearer