I feel like I must be missing something here. I think I'm following the right steps, yet my answer doesn't match one of the choices. 1. The problem statement, all variables and given/known data A Mass of 3.0kg is hung from a spring, causing it to stretch 12 cm at equilibrium. The 3.0kg mass is then replaced by a 4.0kg mass and the new block is released from the unstretched position. How far will the 4.0kg mass block fall before its direction is reversed? a) 9 cm b) 18 cm c) 24 cm d) 32 cm e) 48 cm 2. Relevant equations Spring Constant- k= F/x 3. The attempt at a solution First, I found the force of the 3kg block. F= 3 * 9.8 = 29.4N Next, I found the spring constant K K= F/x[distance] = 29.4/.12m= 245 I Worked backwards to find the distance traveled by the 4kg block, like this. K=F/x 245= (4*9.8)/x x=.16m = 16 cm Which is not one of the options. Where have I gone wrong? Thanks for any help, it is much appreciated.