Two forces Fa and Fb are applied to an object whose mass is 8.0 kg. The larger force is Fa. When both forces point due east, the object’s acceleration has a magnitude of 0.5 m/s2. However, when Fa points due east and Fb points due west, the acceleration is 0.4 m/s2, due east. Find (a) the magnitude of Fa and (b) the magnitude of Fb.