... B. Foot Rule (cm) | Karl | 1 | 25cm. | 9.85cm. | Centee | 2 | 26cm. | 9.7cm. | Christine | 3 | 24.98 | 9.9cm. | | Average: | 75.98 ÷ 3 = 25.32 | 29.45 ÷ 3 = 9.82 | %error=Exp. Value-Accepted ValueAccepted Value*100 Experimental value: 1 inch = 2.5 cm. Accepted value = 1 inch. = 2.54 cm. %error=2.54-2.52.5*100=7.2% Experimental value: 1 inch =26.8cm (meter stick) Accepted Value = 25.0 cm %error=26.8-2525*100=4% IV. Conclusion * The Metric system is based on increments of the number 10 in both volume and linear measurements. The units of linear measure are: Kilometer - 1,000; hectometer - 100; decimeter - 10; base - 1; decimeter - .1; centimeter - .01; millimeter - .001. While The English system of linear measurement is based on inches, feet, yards; 12 inches in a foot, 3 feet in a yard, 5,280 feet in a mile, etc. V. Post- Laboratory Questions 1. Discuss the merits of the metric and English systems of measurements. * In metric the measurements will be easier because of it is multiples of 10. 2. Why are several observations taken for each measurement? * The more trials would take, the more accurate it will be measure. 3. Is it advisable to start measurements at a mark other than the end of a foot rule or a meter stick? * It is a good idea to start measuring from the 1 cm or the 10 cm mark on a meter stick since the ends of the...
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...Measurement and Density The objectives of this experiment were to determine whether there is a difference between the density of Coke and Diet Coke. We also looked at the significant difference of the average densities within each tool used to measure the volume of the sample. Within this experiment we were able to see the impacts of different kinds of error. Random error is inevitable and causes measurements to be a little high and a little low. Averaging several measurements can reduce random error. Systematic errors are caused by equipment malfunction. These cause readings to be always high or always low. This can be corrected by using a different experimental setup. Gross errors are mistakes made by the student that could cause the measurement to deviate from the mean of other measurements. My hypothesis was that there would not be a difference in the densities of Coke and Diet Coke. Since the only difference between Coke and Diet Coke is the sugar in Coke compared to the sweeteners in Diet Coke I did not think there would be a significant difference between the two drinks. The data proved my hypothesis wrong. These sweeteners must have a different mass. From the results of my experimental data, the density of Coke is slightly higher than Diet Coke. The density of Coke averages out to be between 1.0-1.03 g/mL. The density of Diet Coke averages out to be between 0.95-1.00 g/mL. There was a difference in the densities of Coke and Diet Coke between the glassware. The Volumetric...
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...Introduction The first lab involved measuring g or measuring acceleration due to gravity. To measure the values of g we used two steel balls of different sizes, and dropped both balls from different heights. First we started by measuring the masses of each ball with the small steel ball having a mass of 15.8 grams, while the larger one had a mass of 28.8 grams a 13 gram difference. Then we dropped each ball from the same height starting at 87 centimeters. This measurement was from the bottom side of the ball to the timer pad. After both balls had been dropped at least three times from the same height, we would then change the distance that the balls fell. The height ranged from 87 centimeters down to 33.4 centimeters. The team measured the time that it took for each ball to drop from the starting point to the ground. We took a time measurement three times to be sure we some consistency. The following equipment was used to perform the experiment: * One 15.8 g steel ball * One 28.8 g steel ball * Timer (ME 9215A-1) * Triple Balance Beam (PHY 28) * Free Fall Apparatus (ME-9207B), Measuring Tape (39395). References and Sources Ellis, Steven. University of Kentucky Department of Physics and Astronomy Physics 241 Spring 2012 Laboratory Manual. 30 January 2012 Google Earth google.com 31 January 2012 Record of Post Lab Meetings Meeting #1 Attendees: Mattie Conley, Matt Hudzinski, and Reece Glenn Task: Finish Calculating analysis and tables used...
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...Uncertainties in Measuring Devices All measured quantities have uncertainties associated with them. The purpose of error analysis is to determine how such uncertainties influence the interpretation of the experimental results 1. Systematic Error - Results from consistent bias in observation (ie. Instrument-calibration error, natural errors or personal error). - Can be eliminated by pre-calibrating against a known, trusted standard. - Affects accuracy 2. Random Errors - Results from fluctuations in the readings of a measurement apparatus, experimenter's interpretation of the instrumental reading or randomly changing conditions (weather, humidity, etc.). - Can be reduced by averaging multiple measurements. - Unbiased - Affects precision Uncertainties in Measuring Devices General rule of thumb used to determine the uncertainty in a single measurement when using a scale or digital measuring device. 1. Uncertainty in a Scale Measuring Device is equal to the smallest increment divided by 2. 2. Uncertainty in a Digital Measuring Device is equal to the smallest increment. In general, any measurement can be stated in the following preferred form: The measured value is just an estimate and thus it cannot be more precise than the uncertainty of the device. (i.e. The number of decimal places for the measured value must match the number of decimal places for the uncertainty, and in multiples of the uncertainty)” Example: The smallest increment in a meter rule (scale measuring device)...
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...What demographic variables were measured at least at the interval level of measurement? The age which is measured in years, the number of hours per week, annual income in dollars, return to work in weeks and the length of labor which is measured in hours could all be measured in interval level of measurement. They have fixed interval thus making it suitable for this kind of measurement. 11.2 What statistics are used to describe the length of labor in this study? Were these appropriate? In this research there was a controlled group and experimental group. In length of labor mean and standard deviation were used. It is appropriate method to use since the results will be generalized for the whole population. 11.3 What other statistic could have been used to describe the length of labor? Provide a rationale for your answer. Interval level of measurement was used for this research. Instead of interval level we could have used nominal which would have used frequencies, percentages, and mode. It would provide the most common length of labor present. 11.4 Were the distributions of scores similar for the experimental and control groups for the length of labor? Provide a rationale for your answer. No the distribution for both groups were different. The experimental group (7.78) had a slighter higher standard deviation than the controlled group (7.2). The mean for the experimental group was 14.63 while that for the controlled group was 12.79. Standard...
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...found in literature to the values calculated through experiment to determine experimental uncertainty. Keeping all in mind our main objective is to design an experiment to reduce uncertainty. Background and Theory When a dense particle falls through a fluid of lesser density, the gravitational force F_g causing the particle to fall is opposed by a buoyancy force F_b and a drag force F_d as shown in figure 1. If the particle falls at a constant velocity the forces can be expressed as- F_g= F_d+F_b………(1) We know that gravitational force F_g is given by F_g=mg= ρ_s Vg =(1/6)nD^3 ρ_p g………(2) The buoyance force can be derived as the following with the Archimedes Principle taken onto account F_b=(1/6)nD^3 ρ_L g………(3) We can solve for drag force F_d by combining the values of F_(b )& F_g in equation (1), which gives us F_d=(1/6) nD^3 g(ρ_p- ρ_L )………(4) The drag force is a function of 4 independent variables F_d=f (D,V,ρ,μ) where V is the velocity and μ is dynamic Viscosity of the fluid. From Buckingham Pi Theorem we get the value of C_d, which is a dimensionless quantity known as drag coefficient. Drag coefficient is a function of Reynolds number and is given by C_d= F_d/(1/2 ρ_L V^2 π D^2/4)………(5) The Reynolds number is defined as Re= (ρ_L VD)/μ………(6) Figure 1 These measurements will be required to construct relationship between Absolute and Relative uncertainties. Experimental Procedures For this lab we are measuring the Coefficient of drag for three...
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...Measurement and Measurement Error PHYS 1313 S06 Prof. T.E. Coan Version: 16 Jan ’06 Introduction Physics makes both general and detailed statements about the physical universe and these statements are organized in such a way that they provide a model or a kind of coherent picture about how and why the universe works the way it does. These sets of statements are called “theories” and are much more than a simple list of “facts and figures” like you might find in an almanac or a telephone book (even though almanacs and telephone books are quite useful). A good physics theory is far more interested in principles than simple “facts.” Noting that the moon appears regularly in the night sky is far less interesting than understanding why it does so. We have confidence that a particular physics theory is telling us something interesting about the physical universe because we are able to test quantitatively its predictions or statements about the universe. Indeed, all physics (and scientific) theories have this “put up or shut up” quality to them. For something to be called a physics “theory” in the first place, it must be falsifiable and therefore must make quantitative statements about the universe that can be then quantitatively tested. These tests are called “experiments.” The statement, “My girlfriend is the most charming woman in the world,” however true it may be, has no business being in a physics theory because it simply cannot be quantitatively...
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...measured at least at the interval level of measurement Education is measured at the interval scales because the data is measured on specific intervals, and grades of education. 2) What statistics were used to describe the length of labor in this study? Were these appropriate? Length of Labor is measured in hours. It is s an appropriate measurement because the time measured is less than a 24 hours. 3) What other statistic could have been used to describe the length of labor? Provide a rationale for your answer Length of Labor could have been measure in minutes for more accurate measurement. 4) Were the distributions of scores similar for the experimental and control groups for the length of labor? Provide a rationale for your answer. Both groups showed similar scores, well inside the first standard deviation. 5 ) Were the experimental and control groups similar in their type of feeding? Provide a rationale for your answer. The percentages of both the groups were similar in the type of feeding. The differences in the scores are a result of difference in the number of subjects. 6) What was the marital status mode for the subjects in the experimental and control groups? Provide both the frequency and percentage for the marital status mode for both groups. The frequency and percentage for the marital status mode for both experimental and control groups. Marital status was...
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... M2 =171.25 g Mean acceleration = 0.5992 m/s^2 Standard deviation 0.05463 Data Analysis Part 1 (Atwood’s Machine) – Formula and calculation of theoretical acceleration (ath) – A =(m1-m2)/(m1+m2) * g , ath= (0.17125-0.15125)/( 0.17125+0.15125)* 9.79 = 0.6083 m/s^2 % error = 0.05463/0.5592 *100 =9.76 % Formula and calculation of percent difference between ae and ath – % difference = (difference / A_th) *100 = (0.55992-0.6083) /0.6083 *100 =8.01% Part 2 (Springs in Series) – Hooke’s law equation – F = -Kx Calculation of spring constants, k1 and k2 using Hooke’s law equation – k1 = mg/ x = (2.75)/0.052 =52.9 k2 = mg/ x = (7.73)/ 0.058 = 90.9 Calculation of experimental keff for series combinations of springs – K eff = Fs / del(xs ) K = F/x =10.31 /0.052 =198.32 N/m Derivation of equation of theoretical keff – F = kx , F =mg X =...
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...at the interval level of measurement? 2. What statistics were used to describe the length of labor in this study? Were these appropriate? 3. What other statistic could have been used to describe the length of labor? Provide a rationale for your answer. 4. Were the distributions of scores similar for the experimental and control groups for the length of labor? Provide a rationale for your answer. 5. Were the experimental and control groups similar in their type of feeding? Provide a rationale for your answer. 6. What was the marital status mode for the subjects in the experimental and control groups? Provide both the frequency and percentage for the marital status mode for both groups. 7. Could a median be determined for the education data? If so, what would the median be for education for the experimental and the control groups? Provide a rationale for your answer. 8. Can the findings from this study be generalized to Black women? Provide a rationale for your answer. 9. If there were 32 subjects in the experimental group and 36 subjects in the control group, why is the income data only reported for 30 subjects in the experimental group and 34 subjects in the control group? 10. Was the sample for this study adequately described? Provide a rationale for your answer. Exercise 16 MEAN AND STANDARD DEVIATION 1. The researchers analyzed the data they collected as though it were at what level of measurement? a)...
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...This cover page must be submitted with the assignment ME 3057 - EXPERIMENTAL METHODOLOGY & TECHNICAL WRITING Report/Worksheet/Writing Task: Lab number 2 Full Report: Partial Report: X Lab section: J NAMES: Shameek Agarwal, Date Turned In: 2/4/2012 , , Date Returned by TA: ____________________ Grader: _____________ The effort / participation in this laboratory and lab report is divided as follows: Name: Shameek Agarwal, primarily responsible for sections: Name: Name: Name: , primarily responsible for sections: , primarily responsible for sections: , primarily responsible for sections: By submitting this lab report electronically, I/we are agreeing to the following honor pledge, which is consistent with the rules described in the laboratory manual, the syllabus and in class: On my honor, I / we pledge that I / we have neither given nor received inappropriate aide in the preparation of this lab report. The only laboratory reports from prior semesters that I / we have viewed, reviewed, or used in any way were provided by the laboratory TAs during office hours. I / we have reviewed the consequences of using prior laboratory reports in the laboratory manual. GRADE: / Grader Initials: ________ COMMENTS (grader / students) ME 3057 Score Tally for Reports: Abstract: ____________ / Introduction and Procedure: ____________/ Experimental Results: Discussion: Conclusions: Display Format: ____________ / ____________ / ____________ / ____________ / ME3057, Spring...
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...EXERCISE 11 Questions to be Graded 1. What demographic variables were measured at least at the interval level of measurement? 2. What statistics were used to describe the length of labor in this study? Were these appropriate? 3. What other statistic could have been used to describe the length of labor? Provide a rationale for your answer. 4. Were the distributions of scores similar for the experimental and control groups for the length of labor? Provide a rationale for your answer. 5. Were the experimental and control groups similar in their type of feeding? Provide a rationale for your answer. 6. What was the marital status mode for the subjects in the experimental and control groups? Provide both the frequency and percentage for the marital status mode for both groups. 7. Could a median be determined for the education data? If so, what would the median be for education for the experimental and the control groups? Provide a rationale for your answer. 8. Can the findings from this study be generalized to Black women? Provide a rationale for your answer. 9. If there were 32 subjects in the experimental group and 36 subjects in the control group, why is the income data only reported for 30 subjects in the experimental group and 34 subjects in the control group? 10. Was the sample for this study adequately described? Provide a rationale for your answer. (Grove 79) Grove, Susan K. Statistics for Health Care Research: A Practical Workbook. W.B. Saunders Company, 022007...
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...Chapter 9: 1. Distinguish between the following: a) Internal validity and external validity. b) Preexperimental design and quasi-experimental design. c) History and maturation. d) Random sampling, randomization, and matching. e) Environmental variables and extraneous variables. a) Validity is defined in experimentation as whether a measure accomplishes what we think previously or not. There are different types of validity, but the two main varieties are internal and external validity. Internal validity answers the question- do the obtained results have a relationship with what we demonstrated in the experiment? Does the experiment show the real cause of what we draw in the conclusion? It is judged by how well it meets the seven internal validity threats. External validity explain if the observed causal relationship can be generalize among persons, settings, and times. It concerns with the relationship between experimental treatment and other factors. It is used when we have larger population. b) Preexperimental designs are used to control contamination of the relationship that exists between independent and dependent variables. This design is very weak because it fails to control the threats to internal validity or to provide comparison groups that are truly equivalent. Quasi-experimental designs are field experiments that are more advanced than preexperimental. They have control over some of the variables. Using this experiment, we cannot...
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...between the angle of incidence θi and the angle of refraction θr is given by Snell’s law, which states that Where n1 is the refractive index of the medium from where the ray of light enters a different medium and n2 is the refractive index of that different medium. (Usually called medium 1 and medium 2). In order to verify this law experimentally, you could design an experiment based on that relationship. Selecting the right variables would allow to plot a graph of sin θr against sinθi and the gradient of the line would allow you to determine the value of the index of refraction of the piece of glass. The next sketch graph justifies this statement. With the aid of the gradient, you could determine an experimental value of index of refraction of the acrylic block. This result could be compared to the value stated by the manufacturer of the block, or a standard value given in a textbook. This allows to verify experimentally that sin θr is proportional to sinθi and the constant of proportionality should coincide with the ratio of the refractive index of the two media. Selecting and controlling variables Independent variable: Angle of incidence Symbol | Unit of...
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...Schawlow’s Ruler Every color on the visible light spectrum has a distinct wavelength. These wavelengths can be measured by using the diffraction pattern of the light. In this experiment we used a HeNe laser and a green laser pointer with known wavelengths of 632.8x10-9m and 532.0x10-9m respectively. We aimed the lasers at a slight angle from horizontal onto a precision steel ruler with 0.5x10-3m and 1.0x10-3m rulings. When the laser is incident on the rulings, it reflects onto a surface showing the diffraction pattern. After measuring the spacing between each bright spot, we calculated the wavelength for each ruling used for the HeNe laser and for the green laser pointer. The measured wavelength for the HeNe laser at 0.5x10-3m rulings is (632.6±1.3)x10-9m and 1.0x10-3m rulings is (632.6±1.4)x10-9m. For the green laser point the measured wavelength is (632.6±1.4)x10-9m. I. Introduction Every color of light has a diffraction pattern specific to its wavelength. In this experiment we used a ruler to determine the wavelength (λ) of a HeNe laser. The HeNe laser has a known wavelength of 632.8x10-9m. We also measured the wavelength of a green laser pointer with a known wavelength of 532.9x10-9m. This experiment was first done by A. L. Schawlow in 1965 at Stanford University.1 II. Setup and Procedure We used a steel precision ruler with two different spacing’s between the rulings: d=0.5x10-3m and d=1.0x10-3m. We aimed the HeNe laser at a shallow angle (measured...
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