A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Babynini

  • one year ago

Two wires tether a balloon to the ground as shown, how high is the balloon above the ground? I've done it twice..

  • This Question is Closed
  1. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1434516280906:dw|

  2. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @sdfgsdfgs

  3. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @mukushla

  4. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1434516477919:dw|

  5. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is that correct?

  6. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @zepdrix :)

  7. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @rational

  8. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the answer I keep getting for height = 371.78 but that's not correct o.0

  9. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    |dw:1434517128031:dw| I would solve it this way: \[\large \tan 75=\frac{h}{100+x}\ ..........(1)\] \[\large \tan 85=\frac{h}{x}\ .........(2)\] Rearranging (2) we get: \[\large x=\frac{h}{\tan 85}\ ..........(3)\] Plugging the value for x from (3) into (1) gives: \[\large \tan 75=\frac{h}{100+\frac{h}{\tan 85}}\ ..........(4)\] Now solve (4) to find the value of h.

  10. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Equation (4) rearranges to give: \[\large 100 \tan 75 +\frac{h \tan 75}{\tan 85}=h\ ..........(5)\] Can you solve h?

  11. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Um.. 373.205+ (htan(75))/11.43

  12. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How do I solve for h if h is in the left side as well?

  13. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Putting values into (5) we get: \[\large 373.2+0.3265h=h\ ........(6)\] Subtracting 0.3265h from both sides gives: \[\large 0.6735h=373.2\ ..........(7)\]

  14. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    You mean 0.6735h= - 373.2 (notice this side is negative)

  15. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How did you get 0.6735?

  16. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No, 373.2 is not negative. \[\large \frac{h \tan 75}{\tan 85}=0.3265h\]

  17. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorry, I got lost on part 7 We have 373+0.32658h=h (6) if we subtract 0.32658h from both sides we would get 373=h-0.32658h

  18. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    373=h-0.32658h 1.00000h -0.32658h=?

  19. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ah, gotcha. Ok :P

  20. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Cool!

  21. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So now we divide 373 by 0.6735

  22. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Correct.

  23. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and get 554, which is the correct answer :P

  24. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    what was I doing that was wrong?! o.o

  25. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    You needed to form a pair of simultaneous equations to solve this question. Notice I added another variable x to the drawing. Of course we do not need to find the value of x (although we could by substitution).

  26. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Right, I used tan first and then used the Law of Sines..

  27. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Your equation tan (theta) = y/100 is not understood by me. Where is y in the drawing?

  28. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ai, I meant tan(theta)=x/100

  29. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1434519774006:dw| tan(75)=x/100 100tan75)=373.205 Then I did the law of sines a/(sin85) = x/sin90 a= (xsin85)/(sin(90)) so the height = 371.78

  30. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The equation for finding the x? to use tangent It needs to be a right triangle?

  31. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    The triangle with x, 75 degrees and a side length of 100 units is not a right angled triangle. Therefore your equation is not valid.

  32. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    In your usage of tan in a triangle, the triangle must be a right-angled type.

  33. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh gosh, I didn't know that. That's really good to know o.0

  34. kropot72
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    You're welcome :)

  35. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok, thanks :)

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

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.