Answer:
84.1 m
Step-by-step explanation:
Given :
The distance from the ship to submarine :
20 + y
Using Pythagoras :
Tan θ = opposite / Adjacent
Tan θ = 20 / 12
12 tan θ = 20
θ = tan^-1(20/12)
20
θ = 59.036°
The angle phi;
n1sinθ1 = n2sin θ
Sin 59.036 = 1.33 * sin phi
Sin phi = sinsin(59.04) ÷1.33
0.8574907 = 1.33 * sin phi
Sin phi = 0.8574907 / 1.33
Sin phi = 0.6447298
phi = sin(0.6447298
Phi = 40.15°
From Pythagoras :
y = 76tan40.15°
y = 76 * 0.8435707
y = 64.11
20 + y
20 + 64.11 = 84.11