14.47 Four small disks A, B, C, and D can slide freely on a friction- less horizontal surface. Disks B, C, and D are connected by light rods and are at rest in the position shown when disk B is struck squarely by disk A which is moving to the right with a velocity vo = (38.5 ft/s)i. The weights of the disks are W₁ = WB = Wc = 15 lb, and WD = 30 lb. Knowing that the velocities of the disks immediately after the impact are VA VB = (8.25 ft/s)i, vc = vci, and vp = ppi, determine (a) the speeds vc and up, (b) the fraction of the ini- tial kinetic energy of the system which is dissipated during the collision. == = A D B 3 ft 3 ft

Problem 14.2 A 40 lb door with a width of 36 inches has a spring with an unstretched length of 4 in designed to close the door when left open. The spring is anchored as shown below when closed (solid outline is closed, dotted outline is open 90°). If we want the door to have an angular velocity of .2 rad/s upon closing when released from rest at 90°, what should the spring constant of the spring be? (This is the top view of the door below) 3 in (Solution: k = 2.68 lbs/ft=.224 lbs/in) Problem 14.3 4 in M 36 in

Required information NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A loading car is at rest on a track forming an angle of 25° with the vertical when a force is applied to the cable attached at C. The gross weight of the car and its load is 5495 lb WG, and it acts at point G. Know the tension in the cable connected at C is 5000 lb Tc. Neglect friction between the car and the track. 24 in. 25 25.in. T 25 in. C B 30 in. Determine the distance the car moves in 20 s. (You must provide an answer before moving on to the next part.) The distance the car moves is I

Required information NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Two uniform cylinders, each of mass m = 7.5 kg and radius r= 125 mm, are connected by a belt as shown. The system is released from rest when t = 0. B Determine the velocity of the center of cylinder A at t = 3.6 s. The velocity of the center of cylinder A is m/s ↓.