Answer:
[tex]d=0.17m[/tex]Explanation: Each year a volume of 15,000 cubic meters is taken from the lake for 15 years, the lake has a surface area of 1.35 square kilometers and a depth of 4m. We have to find the fall in the depth of the river after 15 years:
The total water taken out of the lake in 15 years is:
[tex]\begin{gathered} T=(15,000m^3)\times15=225,000m^3 \\ \\ T_w=225,000m^3 \end{gathered}[/tex]Therefore the fall in height is:
[tex]\begin{gathered} A\times d=(225,000m^3) \\ \\ \\ A=1.35km^2=1,350,000m^2 \\ \\ \\ A=1,350,000m^2 \\ \\ \\ \therefore\Rightarrow \\ \\ \\ (1,350,000m^2)d=(225,000m^3) \\ \\ \\ \\ d=\frac{(225,000m3)}{(1,350,000m^2)}=0.1666666666 \\ \\ \\ \\ d\approx0.17m \\ \end{gathered}[/tex]Therefore the height of the lake will reduce by 0.17me.
