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Vector question

A ship sails 14 km east them 9km south east .

Calculate the displacement of the ship from its starting point .

I want to use the cosine rule to find the displacement however I need an angle and I can’t seem to find it ,
(edited 6 years ago)
Original post by FGHhgkij
A ship sails 14 km east them 9km south east .

Calculate the displacement of the ship from its starting point .

I want to use the cosine rule to find the displacement however I need an angle and I can’t seem to find it ,


What bearing is East?

What bearing is South-East?

Draw a diagram and mark them on.

Post it if you're still stuck.
Reply 2
Original post by ghostwalker
What bearing is East?

What bearing is South-East?

Draw a diagram and mark them on.

Post it if you're still stuck.


I’ve done that. But still
Original post by FGHhgkij
A ship sails 14 km east them 9km south east .

Calculate the displacement of the ship from its starting point .

I want to use the cosine rule to find the displacement however I need an angle and I can’t seem to find it ,


you could do trig if there is a right angle
Original post by FGHhgkij
I’ve done that. But still


Show your diagram, as that’s kinda essential for a question like this
Reply 5
Original post by Danny7867
you could do trig if there is a right angle


There’s no right angle if you draw the triangle
Reply 6
DE3E8C47-18D5-4DAA-A6E7-302F4A163F16.jpg I figured it’s not a right triangle . I was thinking of using cosine rule but I’m not given an angle .
@RDKGames
Original post by FGHhgkij
I figured it’s not a right triangle . I was thinking of using cosine rule but I’m not given an angle .
@RDKGames


You can use the cosine rule because you can deduce the angle between the 14km and 9km lines.
If you extend the 14km line a bit (dot the extension as it's not part of the actual line), then you can notice that the angle between this dotted line and the 9km line is 45 degrees. Think about it. Hence you can deduce the one in between the two sides.
Reply 8
Original post by RDKGames
You can use the cosine rule because you can deduce the angle between the 14km and 9km lines.
If you extend the 14km line a bit (dot the extension as it's not part of the actual line), then you can notice that the angle between this dotted line and the 9km line is 45 degrees. Think about it. Hence you can deduce the one in between the two sides.


Thanks

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