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Lab 4: Newton’s 2nd Law g by Atwood’s Machine Ben Wildeboer Calc-based Physics I Three Rivers CC September 26, 2011 Description The purpose of this lab was to determine the value of g using Atwood’s Machine and measuring the acceleration. Data and Measurements See attached sheet. Calculations Part I: Determining acceleration of the system ∆y = 0.650 m m1 = .200 kg m2 = .210 kg average t = 2.402 s y = y0 + 21 at2 2(∆y) a= t2 (2(0.650 m) a= = 0.2253 m/s2 (2.402 s)2 Part II: Using acceleration of the system to find g F1 + F2 = Fg1 − Fg2 m2 a + m1 a = m1 g − m2 g (m2 + m1 )a = (m 1 − m2 )g m2 + m1 a g= m2 − m1 0.210 kg + 0.200 kg 0.410 kg 2 g= 0.2253 m/s = 0.2253 m/s2 = 9.2373 m/s2 0.210 kg − 0.200 kg 0.010 kg 9.80 m/s2 − 9.2373 m/s2 % error = = 0.0574 or 5.74% 9.80 m/s2 1 Conclusions This lab demonstrated Newton’s 2nd law by showing unbalanced forces result in an acceleration. Using that acceleration, we found we were able to fairly closely approximate the value for g. Though our calculated magnitude for g showed an error of 5.73%, this is a fairly close value considering possible errors such as human timing, friction from the pulley, and the use of a nonmassless string. 2