Question

Length =density ÷stress .
how?

Answer 1

Length = Stress / ρg

Explanation: The density of a substance is its mass per unit volume. the symbol most often used for density is ρ.

stress is a physical quantity  that defines force per unit area applied to a material.

Density = mass/volume

ρ= mass/volume = M / AL

where A = area and

            L = length

   so M = ρAL

     Stress = force / Area = Mg/A = ρLAg/A

       length = stress /ρg