1 # TP1 10.29 Two Masses fixed to walls
2 # Two equal masses m are connected to each other by a spring (spring constant D) and on either side to a fixed wall.
4 # m*s1'' + 2D*s1 - D*s2 = 0 => s1'' = -D/m*s1 -D/m*s1 + D/m*s2
5 # m*s2'' + 2D*s1 - D*s1 = 0 => s2'' = -D/m*s2 -D/m*s2 + D/m*s1
7 coefficient(1): D/m_1 # D/m for s1
8 coefficient(2): D/m_2 # D/m for s2, identical to D/m_1
9 coefficient(3): -1 -> -s1_0 # initial position of s1
10 coefficient(4): -1 -> -s2_0 # initial position of s2
12 iintegrate -D/m*s1, -D/m*s1, D/m*s2 -> -s1' # input is s1''
16 invert D/m*s1 -> -D/m*s1
18 iintegrate -D/m*s2, -D/m*s2, D/m*s1 -> -s2' # input is s2''
22 invert D/m*s2 -> -D/m*s2