Lab 6 Physics (1)

Siena College - General Physics 110 Circular Motion Lab Using the same available equipment and a line of questioning similar to that provided in Section I, work with your group to design a clear and specific experiment for Section III that will allow you to investigate the relationship between the physical quantities of speed and mass for an object moving in a circular path at constant speed. Purpose & Procedures ● Briefly summarize, in your own words, the objective(s) of your experiments. ● Describe your experimental procedures in enough detail that another group could recreate your experiments exactly -- not just do experiments similar to yours. ● State what you will measure in your experiments as well as the independent and dependent variable(s). Remember not to vary more than one quantity at a time. ● Include a detailed sketch of your experimental setup(s). 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. B3 Is able to decide what parameters are to be measured and identify independent and dependent variables The parameters are irrelevant. Only some of the parameters are relevant. The parameters are relevant. However, independent and dependent variables are not identified. The parameters are relevant and independent and dependent variables are identified. 3

Siena College - General Physics 110 Circular Motion Lab ● Record all of the data you collected in your experiments in neat, easy to understand tables with units included . A separate table should be produced for each of the relationships between physical quantities that you are investigating. ● Take into consideration the number of trials that your group thinks should be run. ● How did you calculate the speed of the swinging object by using the data you collected? Include at least one step-by-step example of your calculations (if the same calculation was repeated throughout the entire experiment). 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. A9 Mathematical No representation is constructed. The mathematical representation lacks the algebraic part (the student plugged in the numbers right away), has the wrong concepts being applied, signs are incorrect, or progression is unclear. No error is found in the reasoning. However, there may not be fully completed steps to solve the problem or one needs considerable effort to comprehend the progression. No evaluation of the math in the problem is present. The mathematical representation contains no errors and it is easy to see the progression from the first step to the last step in solving the equation. The solver evaluated the mathematical representation. Section 1: Radius(m) Counterweight(g)Time(s) Rev per sec Speed(m/s) Centripetal Force(N) 0.425 150 16.56 1.208 3.19 1.47 0.425 250 14.43 1.386 3.98 2.45 0.425 350 10.90 1.835 4.89 3.43 0.425 450 9.58 2.088 5.56 4.41 0.425 550 7.53 2.656 7.12 5.39 Section 2: Radius(m) Counterweight(g)Time(s) Rev per sec Speed(m/s) .10 100 4.78 2.09 1.28 .20 100 6.62 1.51 1.90 .30 100 7.65 1.31 2.45 .40 100 8.23 1.22 3.07 .50 100 9.77 1.02 3.24 Section 3: Radius(m) Counterweight(g)Time(s) Rev per sec Speed(m/s) .40 57 14.57 1.37 3.44 .40 109 17.00 1.18 2.96 6

Siena College - General Physics 110 Circular Motion Lab Scientific Ability Missing Inadequate Needs Improvement Adequate B7 Is able to identify a pattern in the data No attempt is made to search for a pattern. The pattern described is irrelevant or inconsistent with the data. The pattern has minor errors or omissions. The pattern represents the relevant trend in the data. B8 Is able to represent a pattern mathematically (if applicable) No attempt is made to represent a pattern mathematically. The mathematical expression does not represent the trend. The mathematical expression represents the trend. However, an analysis of how well the expression agrees with the data is not included, or some features of the pattern are missing. The mathematical expression represents the trend completely and an analysis of how well it agrees with the data is included. G1 Is able to identify sources of experimental uncertainty No attempt is made to identify experimental uncertainties. An attempt is made to identify experimental uncertainties, but most are missing, described vaguely, and/or incorrect. Most experimental uncertainties are correctly identified. However, there is no distinction between random and experimental uncertainty. All experimental uncertainties are correctly identified. There is a distinction between experimental uncertainty and random uncertainty. For section 1 the pattern present was the greater the amount of force pulling on the string the faster the object moved. In the graph you see a linear correlation going upwards showing that the speed is increasing. In section 2 the pattern present was the longer the radius of the object to the tube, the faster the object moved, but the revolutions were slower. In the graph for section 2, the graph also shows a positive correlation between the increasing radius between the object and the tube, and the speed at which the object was going. In section 3 the pattern present was the greater the weight present, the slower the object moved in circular motion. In the graph for section 3, we see that there is a negative correlation between the weight being added and the speed of the object. Some uncertainties that could contribute to our measurements is the fact that the string would get tangled up in the tube at times causing us to restart the timer. Another issue was that there were times where the weights would fall off the mass holder causing us to restart the timer. Another factor could be human error where there would be a slight delay when starting and stopping the timer. Section 1 Formula: y=mx + b Y= speed m=avg. speed over force x= centripetal force Section 2 Formula: y=mx + b Y= speed m=avg. speed over radius x= radius of the object Section 3 Formula: y=mx + b 9