A submarine is travelling parallel to the surface of the ocean at a depth of 626 m. It begins a constant ascent

in order to reach the surface after travelling a distance of 4420 m. The ascent takes 35 min.
a) What angle of ascent, or angle of elevation, would the submarine need to make to reach the surface in
4420 m? Answer to the nearest degree.
b) How far did the submarine travel horizontally during its ascent to the surface? Answer to the nearest
metre.

1 answer

a) We can use the tangent function to find the angle of ascent:

tan(angle) = opposite/adjacent

In this case, the opposite side is the vertical distance the submarine needs to travel to reach the surface, which is 626 m. The adjacent side is the horizontal distance the submarine travels during the ascent, which is 4420 m.

tan(angle) = 626/4420

angle = tan^-1(626/4420)

Using a calculator, we get angle ≈ 8.1 degrees when rounded to the nearest degree.

b) We can use trigonometry again to find the horizontal distance travelled during the ascent. The horizontal distance is the adjacent side of the angle we just found, which is 4420 m.

cos(angle) = adjacent/hypotenuse

The hypotenuse is the distance travelled by the submarine during the ascent, which we can find by multiplying the ascent rate (distance/time) by the ascent time:

hypotenuse = (4420/35) * 60 = 7554.3 m

cos(angle) = 4420/7554.3

horizontal distance = adjacent = cos(angle) * hypotenuse

Using a calculator, we get horizontal distance ≈ 2586 m when rounded to the nearest metre.