Answer:
x = 1162.5 W/m²
Explanation:
Since, the power decrease is proportional to the depth of the beam. Therefore, interpolation can be used to find the intensity of power at a depth of 1.25 m. First we calculate the slope from know points:
[tex]Slope = \frac{\Delta y}{\Delta x} \\\\Slope = \frac{(1500 - 3000)\ W/m^{2}}{(2 - 0)\ m} \\\\Slope = -750\ W/m[/tex]
Now, we can find the unknown value by using this slope:
[tex]Slope = -750\ W/m = \frac{(600 - x)\ W/m^{2}}{(2 - 1.25)\ m}\\\\(-750\ W/m)(0.75\ m) = (600 - x)\ W/m^{2}\\x = 600\ W/m^{2} + 562.5\ W/m^{2}\\[/tex]
x = 1162.5 W/m² (Power intensity at depth of 1.25 m)