A 5.7 kg block attached to a spring executes simple harmonic motion on a frictionless horizontal surface. At time t = 0 s, the block has a displacement of -0.70 m, a velocity of -0.80 m/s, and an acceleration of +2.7 m/s2. The amplitude of the motion is closest to:
1) A 2 . 3 kg object moving at 7.3 m/s collides inelastically with a 4.0 kg object which is initially at rest. What percentage of the initial kinetic energy of the system is lost during the collision?