Answer:
[tex]t_2=40h[/tex]
Explanation:
We need to bring to mind the non steady equation,
[tex]\frac{x^2_1}{Dt_1}=\frac{x^2_2}{Dt_2}[/tex]
[tex]\frac{x2^_1}{t_1}=\frac{x^2_2}{t_2}[/tex]
We need to write this simplified non steady equation for the two different condition, so
[tex]\frac{x^2_1}{t_1}=\frac{x^2_2}{t_2}[/tex]
[tex]\frac{2.5^2mm}{10h}=\frac{5^2mm}{t_2}[/tex]
[tex]t_2=25*\frac{19}{6.25}[/tex]
[tex]t_2=40h[/tex]