20.6.15
The kinetic potential of the system is L = 1.5x12 + 9x22 + 6x1x2 - 6x12. From the differential equation of motion corresponding to the generalized coordinate x1, determine the acceleration x2 at the time when the generalized coordinate x1 = 0.1 m, and the acceleration x1 = 1 m / s2. (Answer -0.7)