일반물리학 1 — Force and Motion-II: Problem 21

21 In Fig. 6-27, a 15 kg sled is attached to a 2.0 kg sand box by a string of negligible mass, wrapped over a pulley of negligible mass and friction. The coefficient of kinetic friction between the sled and table top is 0.040. Find (a) the acceleration of the sled and (b) the tension of the string.