Finding Direction of Boat Movement: Bearing Calculation

AI Thread Summary
The discussion centers on calculating the bearing of a boat moving with a velocity of -1 + 6j. There is confusion regarding whether bearings should be measured clockwise or counterclockwise, with the mark scheme indicating a bearing of 351 degrees, which is counterclockwise. Clarification is provided that bearings are indeed taken counterclockwise, and the angle next to Alpha is 9 degrees. Additionally, the correct method for finding relative velocity involves vector subtraction, specifically A - B. Understanding these concepts is crucial for mastering bearings in mechanics, especially before an upcoming test.
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Homework Statement


A boat is moving with constact velocity -1 + 6j.
Find the direction in which the boat is moving, giving your answer as a bearing.


The Attempt at a Solution



http://img483.imageshack.us/img483/2457/bearintgsxk3.jpg
Alpha is the bearing I want right?
In the mark scheme it says 351, its this because they take the bearing in an Anti Clockwise motion. The angle next to Alpha is 9 degrees by the way (rounded).

However, I always thought you ALWAYS take bearings in a clockwise motion?

Can someone please clear up my confusion?

Bearing seems to be my main weak point in Mechanics, and the test is tommorow :|.
Thanks in advance!

P.S: If you're doing the velocity of A relative to B. You minus B from A?
 
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you want alpha + 180.
 
bearing are taken to be CCW
that is why u need alpha only not 180+alpha
also if u want an exact answer try using arctan

and velocity of A relative to B is A-B (yes u minus B from A) but use vector subtraction!
 
Last edited:

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