The energy of an isolated system moving in a straight-line along the x-axis is given by the following equation: E=( 2 kg) Vx^2 -(8 J/m)x. What is the magnitude of the acceleration of this system (in m/s2)?

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)