Part A (Figure 1) depicts the potential energy of a 300-kg pallet that slides from rest down a frictionless roller conveyer ramp, then moves across a frictionless horizontal conveyer, and finally encounters a horizontal spring at x = 4.0 m What is the force constant of the spring? When the pallet encounters the spring, it momentarily comes to rest at Express your answer to two significant figures and include appropriate units. x = 6.0 m ? Value Units Figure