6. Two forces are acting on a 18 kg object. One force has a magnitude of 40 N and is directed east. The other force has a magnitude of 25 N and is directed north. Determine the object's acceleration. 7. Two blocks are connected by a string passing over a frictionless pulley, as shown in Figure 2. When the blocks are in motion, block A experiences a force of kinetic friction of magnitude 4.0. N. The mass of mA is 3.2 kg, and the mass of mB is 4.5 kg. a) Calculate the magnitude of the acceleration of the blocks. b) Calculate the magnitude of the tension in the string. Figure 2