I attached the problem statement only with PART of the solutions. He is using the conservation of energy to find the velocity of the anvil. T=Kinetic energy V sub e=potential energy of the spring V sub g=potential energy of gravity The part I am not understand is how ΔV sub e = 1/2(2.8*10^6)(0.024)^2+29.4(10^3)(0.024) J Why do they have the 29.4(10^3)(0.024) there?? That's potential energy of gravity. My professor said the answer was right and that he has checked over it, but he takes a long time to respond so I'm asking it on here.