Is mass or length the independent variable?

Question

I need to graph mass and the length to find an unknown mass? But which goes on the x axis?

Answer 1

you're describing density? given a constant cross sectional area, you can graph mass vs. length.  It'd probably be linear, so it doesn't matter which goes on which axis.  But since density is mass per unit volume, I'd use mass on the y axis, and length on the X axis.

Answer 2

Indepent is x, so the mass depends on the length, giving length a spot on the x axis

length goes on the x axis