To find the angle of incidence o at which the light should be aimed, we can use the concept of trigonometry.
Let h be the height of the light above the water level. The total distance between the light source and the chest can be represented by the hypotenuse of the right triangle formed with h as one of the side.
Using Pythagoras theorem, we have:
h^2 + 2^2 = (h+3.3)^2
Solving this equation will give us the value of h.
Once we have the value of h, we can find the angle of incidence o using the trigonometric relationship:
sin(o) = h / (h + 3.3)
By substituting the value of h, we can find the angle of incidence o.