Determining the meaning of the slope is clearer if the
numerator and denominator of the slope are each multiplied
by kilogram, then the units for the slope become (N.kg) /
(L.kg). If students have not done this type of analysis before,
the teacher will need to suggest multiplying numerator and
denominator by kg. Now the units can be recognized as the
units for gravitational field strength (g) multiplied by liquid
mass density (ρ), where g = 10 N/kg and ρ = 1.0 kg/L. Thus
the slope represents the density of water times the gravitational
field strength.