1. The problem statement, all variables and given/known data Two large crates, with masses 575 kg and 255 kg, are connected by a stiff, massless spring (k = 7.8 kN/m) and propelled along an essentially frictionless, level factory floor by a constant force applied horizontally to the more massive crate. If the spring compresses 4.7 cm from its equilibrium length, what is the applied force? 2. Relevant equations F=kx? F=ma 3. The attempt at a solution I started by drawing a picture and setting up some free body diagrams. The question kind of confuses me because it just says horizontally but not which way, but if the spring is being compressed then the bigger block is moving towards the smaller block? There is a hint in the homework that says there is a non zero acceleration but I don't understand how you can find it?