Answer:
[tex]\boxed{\text{652 ft}}[/tex]
Step-by-step explanation:
The submersible is diving at a down angle of 15° along the hypotenuse AC of triangle ABC.
Its horizontal track along the surface AB is 1500 ft.
[tex]\begin{array}{rcl}\tan A & = &\dfrac{BC}{AC}\\\\\tan 15^{\circ} & = & \dfrac{a}{1500}\\\\0.2679 & = & \dfrac{a}{1500}\\\\a & = & 1500 \times 0.2679\\& = & \textbf{402 ft}\\\end{array}[/tex]
The submersible was already at a depth of 250 feet when it began the dive.
New depth = 250 + 402 = 652 ft
[tex]\text{The depth after the dive is }\boxed{\textbf{652 ft}}[/tex]
