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SECTION 6.5 • Numerical Modeling in Particle Dynamics 169 The acceleration is determined from the net force acting on the particle, and this (6.12) It is convenient to set up the numerical solution to this kind of problem by num- bering the steps and entering the calculations in a table. Table 6.3 illustrates how to do One advantage of the Euler method is that the dynamics is not obscured—the fundamental relationships between acceleration and force, velocity and acceleration, The Euler method is completely reliable for infinitesimally small time increments, but for practical reasons a finite increment size must be chosen. For the finite differ- The size of the time increment influences the accuracy of the result, but unfortu- nately it is not easy to determine the accuracy of an Euler-method solution without a a(x, v, t) ! ! F(x, v, t) m Step Time Position Velocity Acceleration 0 t 0 x 0 v 0 a 0 ! F(x 0 , v 0 , t 0 )/m 1 t 1 ! t 0 ( 0 t x 1 ! x 0 ( v 0 0 t v 1 ! v 0 ( a 0 0 t a 1 ! F(x 1 , v 1 , t 1 )/m 2 t 2 ! t 1 ( 0 t x 2 ! x 1 ( v 1 0 t v 2 ! v 1 ( a 1 0 t a 2 ! F(x 2 , v 2 , t 2 )/m 3 t 3 ! t 2 ( 0 t x 3 ! x 2 ( v 2 0 t v 3 ! v 2 ( a 2 0 t a 3 ! F(x 3 , v 3 , t 3 )/m . . . . . . . . . . . . . . . n t n x n v n a n The Euler Method for Solving Dynamics Problems Table 6.3 Example 6.15 Euler and the Sphere in Oil Revisited Consider the sphere falling in oil in Example 6.10. Using Solution The net force on the sphere is !F ! 'mg ( bv |