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Sunday, February 3, 2013

Solving Vector Problems

Category: Trigonometry

"Published in Newark, California, USA"

A pilot flew in the direction of 140° from A to B and then in the direction of 240° from B to C. A is 500 miles from B and 800 miles from C. Find the distance of the last flight and the direction from A to C. 

Solution:

The first thing that we have to do is to analyze the problem very well. The given angles are expressed as course. Typically course is measured in degrees from 0° clockwise to 360° in compass convention (0° being north, 90° being east).  
Let's draw the figure to analyze the given word problem as follows


Photo by Math Principles in Everyday Life

Complete further the labeling of the above figure as follows


Photo by Math Principles in Everyday Life

Next, use Cosine Law to solve for the distance of the last flight from A to C











Therefore, the distance of the last flight from A to C is 1,040.0154 miles.

Finally, use Sine Law to solve for the direction of the last flight from A to C












or

Therefore, the direction of the last flight from A to C is 140° + 49°14'50" = 189°14'50".