일반물리학 1 — Force and Motion-I: Problem 37

37 A boy with a mass of 35 kg and a sled with a mass of 6.5 kg are on the frictionless ice of a frozen lake, 12 m apart but connected by a rope of negligible mass. The boy exerts a horizontal 4.2 N force on the rope. What are the acceleration magnitudes of (a) the sled and (b) the boy? (c) How far from the boy’s initial position do they meet?