Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Mimi_x3

  • 3 years ago

Amy is 20m S30°W from a tree. Belinda is 50m 110° T from the same tree. Find the distance between them, to the nearest metre.

  • This Question is Closed
  1. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what do S30°W and 110° T mean ?

  2. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Um, I'm not sure but i think South 30 degrees West , 110 degrees true bearing idk. I haven't done it in ages so I forgot xD

  3. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315630919336:dw|

  4. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    like that ^^^ ?

  5. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315631114054:dw|

  6. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Um, idk , it looks right though xDD

  7. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How can I find the distance between them ?

  8. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315631564224:dw|

  9. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Um, I don't think that it requires sin and cos, its bearings

  10. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315631903573:dw|

  11. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What? There's not values of x and y, how can you use the distance formula ?

  12. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I got the values of x and y using the sin() and cos() in the table I drew above. Rounded to the nearest metre, I get 64 meters distance.

  13. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay, tyvm (:

  14. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    does it make sense ? did you learn this stuff in the past ?

  15. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Not in the past xD, I learnt it year 7 and now I forgot xD But I remember that there's an easier way that doesn't require sin and cos

  16. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Well , if there is an easier way, I hope someone will post it here - coz I'd like to know it too :)

  17. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Hey, you know your diagram what is the angle degrees thing for AB

  18. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what do you mean ?

  19. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1315632702671:dw|

  20. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes we can calculate that - it's 240-110 = 130 degrees

  21. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and you're right that we can make the problem simpler

  22. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yep, there's a formula to calculate it then, was it the sine or cosine formula ? or was it soh cah toa ?

  23. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315633004738:dw|

  24. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1315634036159:dw|

  25. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I would need to calculate to find out - why are you asking ?

  26. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    If that angle can be found, then I can use the sine rule xD

  27. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    are you trying to use the law of the cosines ?

  28. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No, the Sine Rule it says it in my book xD

  29. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    which sine rule ? a/sin(A)=b/sin(B)=c/sin(C) ?

  30. upsilon
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes, that's it @fiddle

  31. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yep that xD

  32. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes, but we only have one angle , that 130 degrees at this point.

  33. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know , but the other angle is 30 right ? the one that I drew

  34. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    why did you pick 30 degrees ?

  35. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    is it becasue sin(30)=1/2 ?

  36. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Well, the question S30°W so that angle is 30 right ?

  37. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315634688115:dw|

  38. upsilon
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No, you can't say that...@mimi|dw:1315634688202:dw|

  39. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The 30 degrees would be relative to the black line I drew.

  40. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah, upsilon says the same thing.

  41. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can it be 60 then, since 90-30 = 60 ?

  42. upsilon
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    You can't decide like that you need the angle to be in ratio with the opposite sides...

  43. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yep

  44. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    but the law of the cosines might work here.

  45. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    http://hyperphysics.phy-astr.gsu.edu/hbase/lcos.html

  46. upsilon
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yea, that will work

  47. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1315635067683:dw|

  48. upsilon
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[d = \sqrt{ a^2 + b^2 - 2*a*b*cos\alpha}\]

  49. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay, tyvm (:

  50. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    http://www.wolframalpha.com/input/?i=sqrt%2820^2%2B50^2-2*20*50*cos%28130%29%29 It's 64 , same answer I got with the first method :)

  51. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok, ty (:

  52. fiddlearound
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and it's much shorter than the first method :)

  53. Mimi_x3
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yup xD. Your method looked so complicated before (:

  54. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.