Precautions and Sources of Error There are several precautions that need to be

Precautions and sources of error there are several

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Precautions and Sources of Error There are several precautions that need to be taken to ensure that quality data is obtained in this lab. First, ensure that the adjustable incline plane and the block are clean and dry. This reduces the error that could occur or change the speed of the block. Also, make sure that both the narrow and wide side are made out of the same material. The data will not be accurate if one is done using the copper side and one is done using the wood side. Another precaution is to check that the tension on the string is parallel to the plane. This may require readjusting the pulley after each trial. For the drag portion of the lab, it is important to do a test run to check that the software is working. Several precautions need to be taken to make sure that the values measured are accurate. First, it is important not to hold the coffee filter too close to the motion sensor or it may not record it. Also, it is important to watch that the filter is falling straight down, not swaying at all, as this will impact the velocity. In this lab, we had several sources of error. First, there is no guarantee that after wiping the surfaces that they were totally dry and clean. This may have impacted our data. Additionally, it is difficult to tell with complete certainty that the block was moving with constant velocity. It may have been accelerating slightly, but impossible to catch with the naked human eye. For the drag portion, we faced a lot of difficulty getting a terminal velocity. Many times there was not two consecutive points that were perfectly parallel at the horizontal asymptote. Many trials had to be run to obtain a quality mean. Although our mean terminal velocity has difference from the theoretical, it could be due to imperfect releases by me and my lab partners. We did our best to reduce any horizontal movement. Additionally, once we got to 8 filters, we were not getting any value close to a terminal velocity. Thus, we had to raise the height of the motion sensor. It is possible that had we done this earlier, we could have obtained better data for the first several terminal velocities. Calculations Part Ia Wooden side was used in our experiment Mass of block: .3998kg Mass of hanger: .05kg Narrow side: Weight of hanger Force of friction Normal force Coefficient of friction .126kg 1.23N 3.91N 0.315 Calculating Narrow side Force of Friction and Normal Force Force Normal: m1g = (.3998kg)(9.8m/s^2) = 3.91N Force of friction = m2g = (.126kg)(9.8m/s^2) = 1.23N
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Coefficient of friction: F k = μ k F N μ k = (1.23N)/(3.91N) = 0.315 Wide side: Weight of hanger Weight of block Force of friction Normal force Coefficient of friction .097kg .3988kg . 9506N 3.91N 0.243 .12kg .4988kg 1.176N 4.89N 0.24 .16kg .5988kg 1.568N 5.87N 0.267 .218kg .9988kg 2.136N 9.7N 0.22 Mean of μ k : (.243+.24+.267+.22)/4 = 0.243 Calculating Standard Deviation of μ k : (.243+.24+.267+.22)/4 = 0.243 [(.243-.243)^2+(.24-.243)^2+(.267-.243)+(.22-.243)^2]\2 = 0.0025 Calculating Normal Force: Trial 1 Force Friction = m2g = (.097kg)(9.8m/s^2) = .9506N Force Normal = m1g = (.3988kg)(9.8m/s^2) = 3.91N Coefficient of friction: F k = μ k F N μ k = ¿ (.9506N/3.91N) = 0.243 *The same method as shown above was used for the other three trials* Part Ib Angle Weight of block Weight of hanger Force friction Normal force μ k Calculate
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