Assume the liquid film in Example 5.9 is horizontal (i. e., θ = 0) and that the flow is driven by a constant shear stress on the top surface ðy=hÞ, τyx =C. Assume that the liquid film is thin enough and flat and that the flow is fully developed with zero net flow rate (flow rate Q = 0). Determine the velocity profile uðyÞ and the pressure gradient dp=dx

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".