Ascending Mass, M Descending Mass, M. F - Mg F-Mg Figure 5: Free body diagram. Two objects with mass hanging on a pulley by string 2. Apply Newton's Second Law to write the equations for M, and Mr. You should get two equations with tension in the string, weight for each mass and accelerations for each mass (8, and a:). M1, T - Mig = M1a1, T = M1(g + 21)---------(1), Equation for M2, M2g - T = M232, T = M2(8- 32)---- ----(2). Equating both equations for T, and 31 = 32 = a, we get M1(g+a) = M2(g-2) Mig + Mia = M2g - M2a a(M1 + M2) = g(M2-M1) a = (M2 - M1)/(M1+M2) 3. Post-Lab Question 2 results in two equations with three unknowns! A third equation is required to solve the system. What is the third equation? 5Fx = max Mg sin(q) =max Ax = g sin(q)