1. The problem statement, all variables and given/known data An 11.5kg mass is traveling to the right with a speed of 2.4m/s on a smooth horizontal surface when it collides with and sticks to a second 11.5 kg mass that is initially at rest but is attached to a light spring with force constant 110N/m. 2. Relevant equations f=1/T T=1/f F=-kx A=v*(sqrt(m/k)) 3. The attempt at a solution I tried to use the equation A=V*sqrt(m/k). I plugged in 2.4 m/s in for v, k is the force constant, 110N/m, and I used 23 kg for the mass (the two masses added together). Solving for this, I get 1.097m. However, this is incorrect. Any ideas where I went wrong? Also, in case it is necessary, I have already solved for the frequency: f=0.348 Hz.