Analysis and Approaches for IBDP Maths Ebook 1 | Page 128

Your Practice Set – Analysis and Approaches for IBDP Mathematics
43
Paper 2 Section B – Bearing and speed problems
Example
A ship is sailing south from a point A towards point D . Point C is 300 km south of A .
Point D is 100 km south of C . There is a lighthouse at E . The bearing of E from A is
128 . The angle AEC is 70 . This is shown in the following diagram.
(a) Find the bearing of A from E .
[2]
(b) Find AE .
[5]
(c) Find DE .
[3]
(d) When the ship reaches D , it changes direction and travels directly to the
lighthouse at 100 km per hour. At the same time as the ship changes direction, a
ferry starts travelling to the lighthouse from a point B . This point B lies on AC ,
between A and C , and is the closest point to the lighthouse. The ship and the
ferry arrive at the lighthouse at the same time. Find the speed of the ferry.
[5]
120
SE Production Limited