Physics Problem
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Thread: Physics Problem

  1. #1
    er0k
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    Physics Problem

    Yes this is my homework.

    The summit of a mountain, 2085 m above base camp, is measured on a map to be 4580 m horizontally from the camp in a direction of 32.4 degrees west of north. What are the x, y, and z components of the dispacement vector from camp to summit? What is its length?

    can anyone do that problem, i have completed it, and know how it works, but im getting really wacky answers when i try to test my answers. even though i know they are right.. someone who can just work it please..

    edit: come on you engineers out there this problem is easy!

  2. #2
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    I don't remember anything about vectors anymore, but can't you simply do the length of that vector using Pythagoras?

    (2085)^2 + (4580)^2 = (vector length)^2

  3. #3
    er0k
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    yeah, i got that, but when i take 2085/sin(32.4) i don't get the same answer, like i should.

  4. #4
    Regal Making Handler
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    (2085)^2 + (4580)^2 = (vector length)^2.............Square root of (vector length)^2=length.........
    What happens if a big asteroid hits the Earth? Judging from realistic simulations involving a sledge hammer and a common laboratory frog, we can assume it will be pretty bad. - Dave Barry

  5. #5
    er0k
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    yep, thats the answer for the length. Now imagine this right triangle we have now. Try to get the answer with trig. can't do it, and i don't know why.

  6. #6
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    Pythagorus's theorm is part of trig. I'm not quite sure what you are asking here. Are you looking for the Angels other than the right angle formed??

    It's been 0ver 20 years since i had to play with sins/cosins and tangents.lol

    Edit

    Take a look here: http://aleph0.clarku.edu/~djoyce/java/trig/right.html
    It should explane it alot better than i can.

    Edit
    What happens if a big asteroid hits the Earth? Judging from realistic simulations involving a sledge hammer and a common laboratory frog, we can assume it will be pretty bad. - Dave Barry

  7. #7
    Senior Member IKnowNot's Avatar
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    Tough day at work and am getting drunk again, but I think I am missing something here ( and it has been at LEAST 20 years for me too )

    You are trying to solve a 3 dimensional question with a single 2 dimensional equation???
    Is some info missing here?

    How about a starting point or ending point?

    The 32.4 degree angle is looking down at the map, not from the side, the elevation is looking at it from the side, not down.
    In other words, if you choose the summit ( because I like positive numbers ) to be along the x-y axis ( 0,2085,0 ) then the base would be somewhere along the x-z axis defined by the right triangle 90 deg by 32.4 deg. by 57.6 deg. Since you know one leg of that triangle ( 4580 ) you should be able to figure out the other legs which should eventually give you the x-y-z coordinates of the base camp. ( hint: the y part would be 0 )

    Now you have the starting point and ending point. From there you should be able to solve the rest.

    Am I too drunk and too old, or did this help?
    " And maddest of all, to see life as it is and not as it should be" --Miguel Cervantes

  8. #8
    er0k
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    The pythagoreun theorem gives you 5082 m as your length. If you take sin(32.4) *2085 you dont get 5082 like you should. Also if you take cos(32.4) * 4850 you dont get 5280, like you should. I was asking why this is true, because it is.

  9. #9
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    er0k if i remember correctly the sin of an angle will allways be less then or equal to one, therefore if you multiply a number buy a sin it will never get bigger...perhaps you are forming the equation wrong.
    Who is more trustworthy then all of the gurus or Buddha’s?

  10. #10
    er0k
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    no i figured it out the other day, the angle i needed to use was much larger... because the angle from the y to the z axis was different than the one for the original vector.

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