일반물리학 1 — Force and Motion-I: Problem 49

49 In Fig. 5-35, a block of mass m = 5.00 kg is pulled along a horizontal frictionless floor by a cord that exerts a force of magnitude F = 12.0 N at an angle θ = 25.0°. (a) What is the magnitude of the block’s acceleration? (b) The force magnitude F is slowly increased. What is its value just before the block is lifted (completely) off the floor? (c) What is the magnitude of the block’s acceleration just before it is lifted (completely) off the floor?