1. The problem statement, all variables and given/known data A 2kg mass and a 3kg mass are on a horizontal frictionless surface, connected by a massless spring with spring constant k=136N/m. An 18 N force is applied to the larger mass. How much does the spring stretch from its equilibirum length? (answer in cm) 2. Relevant equations F=-kd k= 136N/m F=18N 3. The attempt at a solution I did the obvious, I used the equation above and solved for D: 18/136 = 0.132m x 100= 13.2 cm, which is wrong. I obviously neglected the two masses, which is probably where I went wrong? Can anyone help me out by providing the proper equation and solution?