38.
Case Study 3: The Lighthouse (Applications of Trigonometry)
A lighthouse is a tower with a bright light at the top, located at an important or dangerous place regarding navigation (travel over water). A lighthouse keeper is observing two ships from the top of the 75m high lighthouse. The angles of depression of the two ships, approaching the lighthouse in the same straight line, are \(30^\circ\) and \(45^\circ\).
(i)
Draw a neat labeled figure to illustrate the situation. (1 Mark)
(ii)
Find the distance of the closer ship from the base of the lighthouse. (1 Mark)
(iii)
Calculate the distance between the two ships. (Use \(\sqrt{3} = 1.732\)) (2 Marks)
OR
If the ship originally at \(30^\circ\) moves towards the lighthouse and reaches the position of the first ship, how much distance did it cover? (2 Marks)