I am having trouble with this problem: A particle of mass 4.00 kg is attached to a spring with a force constant of 100 N/m. It is oscillating on a horizontal frictionless surface with an amplitude of 2.00 m. A 6.00-kg object is dropped vertically on top of the 4.00-kg object as it passes through its equilibrium point. The two objects stick together. (A) By how much does the amplitude of the vibrating system change as a result of the collision. (B) By how much does the period change? (C)By how much does the energy change? (D) Account for the change in energy? This is pretty much a plug-in problem, but my main question is how to solve for the new amplitude and energy after the collision. I am going over the formulas and it seems like the amplitude is in the formula for energy and energy is part of the formula for amplitude, how can I solve for one or the other when they both change after the collision? Can someone give me a clue?