Pls me asap with (sketch a line that represents the diff shapes) - also indicate which line is what function (random answers gets moderated! )

Since the cross section is of uniform width (front to back), the fill rate (rate of change of depth vertically) is inversely proportional to the horizontal (side-to-side) dimension.

a) The horizontal width is narrow near the bottom, so the fill rate will be relatively fast until the depth where the width changes. Then the fill rate will slow to perhaps 1/3 of what it was.

b) The horizontal width is a linearly decreasing function of depth, so the fill rate will be increasing on a hyperbolic curve--increasingly fast as the depth increases.

c) This is the reverse of case (a). The fill rate is initially slow, then jumps dramatically when the depth reaches the point where the horizontal width suddenly narrows.

It is not clear whether you are supposed to graph fill rate as a function of depth or as a function of time. The desriptions are for fill rate. If you want to graph versus time, these descriptions apply to the slope of the curve, not its level.