A submarine traveling 792 feet per minute is descending at an angle of depression of 5°. How many minutes does it take the submarine to reach a depth of 200 ft?
Here's a similar question: http://www.chegg.com/homework-help/submarine-traveling-90-mph-descending-angle-depression-many-chapter-5.2-problem-58e-solution-9781424089161-exc
The distance, d, that the submarine descends in one minute can be expressed as
sin(5°) = d / 792 multiply both sides by 792
792*sin(5°) = d
So...to find out how many minutes it will take the sub to reach a depth of 200 ft we can evaluate this
200 / [ 792*sin (5°) ] ≈ 2.9 min ≈ 2 min 54 sec