31. A 10-kg box is pushed across the frictionless floor by a 50-N force directed at 36.9° below the horizontal. Calculate: (a) the acceleration of the box, (b) the normal force on the box. [Answer: (a) 4.0 m/s², (b) 130 N]
32. A 20-kg box is pulled across the frictionless floor by a 50.0-N pulling force F1, directed at 36.9° above the horizontal. A 60-N pulling force F2 is applied to the left. Calculate: (a) the acceleration of the box, and (b) the normal force on the box. [Answer: (a) -1.0 m/s², (b) 170 N]