Question 1118829
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*[illustration ShipDisplacement.jpg].


The turn from 70 west of south to bearing 120 is 130 degrees, hence Angle OAB is 50 degrees.  3 hours at 50 km/hr is 150 km, and 4 hours at 50 km/hr is 200 km.  With two sides and the included angle, use the Law of Cosines to calculate the measure of Segment OB, the current ship's displacement from the origin.


Then use the Law of Sines to calculate Angle AOB.  Subtract 70 degrees from Angle AOB, then subtract that difference from 180 degrees to obtain the final bearing.
								
								
John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
<img src="http://c0rk.blogs.com/gr0undzer0/darwin-fish.jpg">
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*[tex \LARGE \ \ \ \ \ \ \ \ \ \  
								
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