Electric instruments on a treasure-hunting ship detect a large object on the seafloor...

Question

Electric instruments on a treasure-hunting ship detect a large object on the seafloor.The angle of depression is 29°, and the instruments indicate that the direct- line distance between the ship and the object is about 1400 ft. About how far below the surface of the water is the object, and how far must the ship travel to be directly over it

Answer 1

Moosh

Draw a right angled triangle. ABC. A is the ship, C is the object, angle ABC is 90° .

Then you need to find distances BC and AB.

Suppose the angle of depression was 31°, and the distance 1500 ft.

Then angle CAB will be 31°, and AC will be 1500 ft.

BC / AC = sin 31°, so BC = AC sin 31° = 772.6 ft

AB / AC = cos 31° so AB = AC cos 31° = 1285.8 ft

Use this model with your numbers !

Mike