Problem: An object of mass m1= 10 kg moving to the right with a velocity v1=30 m/s, collides with a second object of mass m2=5kg, which is initially at rest. The 2 objects stick together, and they continue to move with the same velocity V. The moving system of 2 blocks compresses a light spring, having a spring constant k=80 N/m. Calculate the max. compression distance x, of the spring. m1v1 + m2v2 = (m1+m2)vf (10)(30)+(5)(0)=(10+5)vf 300=15vf Vf=300/15=20 KE=U spring I stuck on how to finish solve the problem.