Answer:
Volume of water = 1800π ≈ 5655m³
Step-by-step explanation:
If we assume that "y" varies from north to south since height varies from south to north. We will obtain;
h(y) = ay + b
Thus,
At, h(-20) = 2 ; 2 = -20a + b ___ eq(1)
At, h(20) = 7; 7 = 20a + b ___ eq(2)
Add eq 2 to eq 1;
7 + 2 = 20a - 20a + b + b
9 = 2b; b = 9/2
Plug in 9/2 for b in eq 2;
7 = 20a + 9/2
Multiply through by 2;
14 = 40a + 9
40a = 14 - 9; a = 5/40 = 1/8
Thus, h(y) = (1/8)a + (9/2)b
The rest of the process involves double integral, so i have attached it for clarity.