A system of two infinitely large parallel plates separated by a gap of 2 mm. The lower plate moves at a speed of 5 mm/s while the upper one remains stationary. The space between the two plates is an Ostwald fluid whose consistency index is 6.5 Pas and its exponent is 0.5. Determine the shear stress. If the speed is halved, determine whether the shear stress is increased or decreased. Similarly, if the gap is reduced by half, determine whether the shear stress is increased or decreased. Based on the results, can it be deduced if the fluid is dilatant or pseudoplastic?