Essay --

David Kim Physics Lab 1 02/11/14 Section: A1 Introduction In Experiment 1, the objective was to weigh 150 pennies and find the best estimate value and the uncertainties for the weight of the pennies. Instrument uncertainty is the least value that can be read from the measuring device. It is always less than or equal to the least count. The least count is the smallest division that can be marked or shown from a certain instrument. The instrument uncertainty is equal to the least count in this experiment. Random errors are simply mistakes that are made due to the instrument being used or the measured object being poorly defined. The total uncertainty of a measurement is calculated by using the instrument uncertainty and the uncertainty due to fluctuation. Uncertainty due to fluctuation is dependent on the average and the total amount of times there was a measurement. This average is found when:  ¯x= 1/N (x_1+x_2+ †¦+ x_n ) N is the total number of measurements, x1 is the first measurement, x2 is the second measurement, and xn is the last measurement. The uncertainty due to fluctuation is found by: ∆x_fl= ÏÆ'_x/√N ÏÆ'_x is the standard deviation of the mean and N is the total number of measurements. Standard deviation can be found by: ÏÆ'_x= √((d_1^2+ d_2^2+ †¦+ d_N^2)/(N-1)) Where d_n(the derivative) is found by: d_n=x_n- x Ì… This in words is: the measurement of the nth term subtracted by the mean. Total uncertainty is found by: ∆x= √(∆x_ins^2+ ∆x_fl^2 ) Where ∆x_ins is the instrument uncertainty and ∆x_fl is the uncertainty due to fluctuation. Initial Data Part A1: Instrument Uncertainty Quiz Student has passed the test The following answers were entered for the digital device # 2: Units g Least count 0.1000 I... ...ould have to take around 300 measurements so that the results would be accurate and precise to the expected value of 100. In part B of the experiment, the standard mass of the penny between 1941 and 1982 was 3.100 g; and between 1983 and 2011, the standard mass was 2.500 g. The standard mass of the penny changed between 1982 and 1983. The mass was decreased by .600 g. Pennies lose or gain weight in circulation because most of the pennies were not 2.5 or 3.1 grams on the dot. The possible rust or erosion from the time it was in circulation helps to describe the range that the mass of the pennies had. In general, most of the measurements were accurate compared to the expected value. The measurements on the most part were accurate. However for the outliers, the rust and the erosion to the penny can describe the mass being significantly higher or lower.