The figure shows a system consisting of three blocks, a light frictionless pulley, and light connecting ropes that act horizontally on the upper two blocks. The 9.0 kg block is on a perfectly smooth horizontal table. The surfaces of the12 kg block are rough, with ?k = 0.30 between the 12 kg and 9.0 kg blocks. The mass M of the hanging block is set so that it descends at a constant velocity of 3.25 m/s. a) What is the mass M of the hanging block? b) The mass M is now changed to 5.0 kg, causing it to accelerate downward after it is released. What is the acceleration of the hanging mass?

5. The gure shows a system consisting of three blocks, a light frictionless pulley, and light connecting ropes that act horizontally on the upper two blocks. The 9.0 kg block is on a perfectly smooth horizontal table. The surfaces of the12 kg block are rough, with uk = 0.30 between the 12 kg and 9.0 kg blocks. The mass M of the hanging block is set so that it descends at a constant velocity of 3.25 mls. a) What is the mass M of the hanging block? b) The mass M is now changed to 5.0 kg, causing it to accelerate downward after it is released. What is the acceleration of the hanging mass? -"D #5; ex