K proportionality constant

[Ninz30]

I don't get what k (proportionality constant) is. Do we ever have to solve for k, or just for the ratio of y1/x1 to y2/x2 and y1x1 to y2x2?
I do not understand what k is when looking at a problem. I get that in direct proportionality y/x=k, and in inverse yx=k, but it a vic problem, i don't understand what it is.

For instance, in the example given in Guide 3, Chapter 5, pg 75, y= max height in feet. x= velocity squared. they are directly proportional, so k = max height ft (y) / v squared (x), which is what exactly? k is not the time is it?

[tim]

in most cases you will want to solve for k in these problems so you can plug it into a second equation. however, there is no need to figure out what k "means". think of it just as a number; in fact, it has no inherent meaning in most problems other than to express a unit-less relationship among the variables..