Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

burhan101 Group Title

Determine the resultant of this vector sum: 10 N at 045 degrees, and 8 N at 68 degrees

  • one year ago
  • one year ago

  • This Question is Closed
  1. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    This isn't so bad. Have you had practice with these?

    • one year ago
  2. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    I can't do it with degrees :S

    • one year ago
  3. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    After a while, they'll become nearly routine!

    • one year ago
  4. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Can you please go through the steps , i find these really confusing

    • one year ago
  5. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Okay! So you've seen these? And have learned that any vector has separate components (x and y)?

    • one year ago
  6. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    We can draw a picture, if you like. Let's look at the first vector, 10N. Sound good?

    • one year ago
  7. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Okay ! :)

    • one year ago
  8. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Alright! |dw:1360640234142:dw| There's the vector in one piece.

    • one year ago
  9. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    How do we know that it's NE ?

    • one year ago
  10. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    That is the trick with degrees, and all you have to remember is this - and it'll be in the next picture. You're working with two dimensional space, here. A great way to draw this is the x and y axes that I bet you're familiar with. Everything has an x and y component, like the vectors. And people like to use angles! So they decided on a common place to start the angle, and where to go from there. I'll show you.

    • one year ago
  11. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360640574984:dw|

    • one year ago
  12. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    OH so that's the common starting point ?

    • one year ago
  13. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    That's the convention. Convention just means it's a proper way to do it in some organization of math rules. So pretty much everybody does this. You could make up your own convention, but it'd be hard to explain it to the rest of us :P

    • one year ago
  14. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yep! Angle measures start from there if no other information is given!

    • one year ago
  15. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ohhh okay

    • one year ago
  16. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360640896289:dw|Now, a person might say, "10 degrees west of north" or something silly like that. That means....

    • one year ago
  17. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    But as a starting point, positive x-axis is what you'll use. Hopefully your teacher agrees. It's a far-reaching convention.. Goes into lots of maths.

    • one year ago
  18. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Now you know where your vector is! And you can split it up with trigonometric functions using the angle!

    • one year ago
  19. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh alright

    • one year ago
  20. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So you have seen that before? Using the trig functions?

    • one year ago
  21. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @burhan101 so you've got it? Congrats and take care if you did!

    • one year ago
  22. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    No

    • one year ago
  23. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i know how to do these with like normal vectors

    • one year ago
  24. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Haha, okay!

    • one year ago
  25. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360641728957:dw|

    • one year ago
  26. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i know thats not right -.-

    • one year ago
  27. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Im so lost lol

    • one year ago
  28. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    You mean like <x,y>? Yeah, this is different. You aren't just told the components. However, you can find them!

    • one year ago
  29. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Have you ever used sine or cosine for angles?

    • one year ago
  30. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yea

    • one year ago
  31. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Well that's what you'll be doing here. Are you well practiced with them? Going back to this picture, |dw:1360642770812:dw|Do you see how to get the x and y components?

    • one year ago
  32. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360642844365:dw|

    • one year ago
  33. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    If not, I can show you.

    • one year ago
  34. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    how do i add the other vector to this picture now

    • one year ago
  35. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Well, vectors are easy to split up into components with sine and cosine. Then you use "vector addition," which really means you just add all like components! Then you have one vector as a result. And it is called the "resultant vector." And it'll be in <x, y> form. You can, however, get it back to how it was, with a given magnitude and given direction (as an angle).

    • one year ago
  36. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Are you giving it a shot?

    • one year ago
  37. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes im trying to draw it out :$

    • one year ago
  38. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    I didn't see the picture you drew before! That's a good rough representation of the vectors! :) Just like mine! :)

    • one year ago
  39. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360643739640:dw| funy thing with vectors is that they are a magnitude (like 10N) and direction (like 45 degrees). They aren't a location. You can the same arrowed line anywheres, and they're still equal vectors.

    • one year ago
  40. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So.. (wait for it...)

    • one year ago
  41. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ohhh

    • one year ago
  42. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360644030205:dw|

    • one year ago
  43. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    aaannnndddd........

    • one year ago
  44. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    The first drawing of the components is common, where the vectors start at the origin. But looking at it this next way will help see sine and cosine's roles.|dw:1360644139377:dw|

    • one year ago
  45. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Actually, nevermind! Retake!

    • one year ago
  46. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360644367333:dw|That one.

    • one year ago
  47. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360644483191:dw|and that one.

    • one year ago
  48. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Do you see where this is going?

    • one year ago
  49. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Not realll dont i add the other 8 N at 068 degrees ?

    • one year ago
  50. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Well, yeah! You have to add its components to the other vectors components. So, first, you have to get each vector's components.

    • one year ago
  51. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Dont you just add then like the tail to tail method and then do tan inverse to find the angle ? :S

    • one year ago
  52. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    them *

    • one year ago
  53. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    You could, huh! But that's sort of what this is. Picture time! :)

    • one year ago
  54. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    okay so im not totally off track

    • one year ago
  55. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360645168898:dw|derfinately not!

    • one year ago
  56. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360645291825:dw|

    • one year ago
  57. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    That last one shows the resultant vector.

    • one year ago
  58. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    OH

    • one year ago
  59. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360645379901:dw|

    • one year ago
  60. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    makes so much sense !

    • one year ago
  61. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\huge :)\]

    • one year ago
  62. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    so now i find the tan inverse right

    • one year ago
  63. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    After you get the components of the resultant vector, you use them to find the magnitude (however many N) and that inverse tangent (y-component divided by x-component) to find the angle.

    • one year ago
  64. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Does that make sense?

    • one year ago
  65. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @burhan101 ?

    • one year ago
  66. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i think so

    • one year ago
  67. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Okay.... Ready to try it?

    • one year ago
  68. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    tan-1 = 68/45

    • one year ago
  69. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i think :S

    • one year ago
  70. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Not quite! Inverse tangent will give you an angle, but you have to give it a y/x amount. Since you want to find the angle of the really big resultant vector, you'll use its y-component divided by its x-component. You'll have those components after you do the adding. Let's break your 10N vector into components for practice. We can even then use those components to re-find the angle!

    • one year ago
  71. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1360646989287:dw|

    • one year ago
  72. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\begin{matrix}x-component&=&10cos(45)&=&7.07\\y-component&=&10sin(45)&=&7.07\end{matrix}\]

    • one year ago
  73. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    And units are N. I'm gonna head to bed. Good luck! If you want to continue on your own, do the same thing to the 8N vector! Then, add the x-components together. Then add the y-components together. Then you have the resultant vectors components. That would be how you knew vectors before.

    • one year ago
  74. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    thanks for your help ! :D

    • one year ago
  75. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    And to rediscover that magnitude and angle of the 10N vector, using it's x- and y-components, Magnitude: Use Pythagorean Theorem.\[\sqrt{x^2+y^2}\] For the angle: Use inverse tangent.\[tan^{-1}{\LARGE (}\frac{y}{x}\LARGE )\]

    • one year ago
  76. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\sqrt{7.07^2+7.07^2}\approx 9.998\approx 10.00\]There was some rounding error to get to 9.998. But if you round it to the nearest hundredth, you have 10! \[tan^{-1}{\LARGE (}\frac{7.07}{7.07}{\LARGE )}=tan^{-1}(1)=45^o\]

    • one year ago
  77. theEric Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Switched back. :) You're very welcome! Take care! Tag me if you need any more help.

    • one year ago
    • Attachments:

See more questions >>>

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.