An aeroplane flies for 4hours from position P on a bearing of N60W To poing Q At an average speed of 60km/hr. the aeroplane then flies on a bearing of 150 from Q To another point R 500km away. Calculate correct to 3 significant figures.

Question

An aeroplane flies for 4hours from position P on a bearing of N60W To poing Q At an average speed of 60km/hr.  the aeroplane then flies on a bearing of 150 from Q To another point R 500km away. Calculate correct to 3 significant figures.
a) the distance /PR/
b) the bearing of R From P.

oobleck · Answer

distance = speed * time
Draw a diagram. You can see that
(a) using the law of cosines,
PR^2 = 240^2 + 500^2 - 2*240*500 cos30°
(b) If P is at (0,0) then R is at (42.15,-313)
so the bearing of R from P is S7°W