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Adding vector components in two dimensions

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Homework Statement


A plane flies 600km/h south. The plane encounters a southwestern wind of 100km/h.

Homework Equations


What is the velocity (magnitude and direction) of the plane

The Attempt at a Solution


What I did was break the 100km southwestern vector into its components. 100*cos45 = 70.71 (45 because southwestern wind is 45deg?). This will be both north and east component since it is 45 45 90 triangle that is being used.

Then I subtract 70.71 north component from 600 original vector = 529.29
Using the new 529.29 south component, and the remaining east pointing 70.71 component, I use phythagoras to find the resulting velocity vector.
I get 534. Answer is 543.

As for the heading, I get 7.61deg, which is inline with the answer.
 

Answers and Replies

  • #2
haruspex
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Homework Statement


A plane flies 600km/h south. The plane encounters a southwestern wind of 100km/h.

Homework Equations


What is the velocity (magnitude and direction) of the plane

The Attempt at a Solution


What I did was break the 100km southwestern vector into its components. 100*cos45 = 70.71 (45 because southwestern wind is 45deg?). This will be both north and east component since it is 45 45 90 triangle that is being used.

Then I subtract 70.71 north component from 600 original vector = 529.29
Using the new 529.29 south component, and the remaining east pointing 70.71 component, I use phythagoras to find the resulting velocity vector.
I get 534. Answer is 543.

As for the heading, I get 7.61deg, which is inline with the answer.
I agree with your answer. Must be a typo.
 
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  • #4
haruspex
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I googled "plane flies in south direction..etc" for similar questions though, and I find on two websites that I still cant get matching answers.
ex: http://www.jiskha.com/display.cgi?id=1254021349
Not sure what you are saying. Do you mean that you submitted an answer to the question there and were told your answer is wrong?
 
  • #5
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No no just that i tried googling that particular question assuming its a "stock question" and people have asked it in the past. I still don't get the same answer as people that have tried to help others on other websites.
 
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haruspex
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No no just that i tried googling that particular question assuming its a "stock question" and people have asked it in the past. I still don't get the same answer as people that have tried to help others on other websites.
Well, the first answer to the question at that link was wrong. It took the wind as from NE instead of SW, so got an answer greater than 515, which is clearly impossible.
 
  • #7
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Oh yea.... haha...

Ok well...hopefully was a typo...534...543.......thank you.
 

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