Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

bii17

  • 2 years ago

A weight is attached to one end of a 33 foot rope which passes over a pulley 18 feet above the ground. the other end is attached to a truck at a point 3 feet above the ground. if the truck moves away at a rate of 2 feet per second, how fast is the weight rising when the truck is 8 feet from the spot directly under the pulley?

  • This Question is Closed
  1. perl
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1349004422200:dw|

  2. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1349004500723:dw|

  3. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I need a solution :)

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

    which direction is the trick moving, it is not clear

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

    |dw:1349004602933:dw|

  6. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1349004739213:dw|

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

    |dw:1349004667017:dw|

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

    |dw:1349004778629:dw|

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

    dx/dt =2 feet per second y is constant..... now, can u find dh/dt

  10. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    how?

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

    |dw:1349004927462:dw|

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

    Since y is constant dy/dt=0 right?

  13. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes. then?

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

    |dw:1349005061647:dw|

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

    Now, given x=8

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

    y=18-3=15

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

    So, |dw:1349005186713:dw|

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

    right?

  19. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @sauravshakya the answer is 16/ 17

  20. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Use of calculus is good

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

    |dw:1349005396208:dw|

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

    Now we need to find dl/dt

  23. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    how to fnd it @sauravshakya

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

    you need a better diagram

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

    A weight is attached to one end of a 33 foot rope which passes over a pulley 18 feet above the ground. the other end is attached to a truck at a point 3 feet above the ground. if the truck moves away at a rate of 2 feet per second, how fast is the weight rising when the truck is 8 feet from the spot directly under the pulley?

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

    |dw:1349005616181:dw||dw:1349005671316:dw|

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

    Did I did some algebra wrong or what???????

  28. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    hmm i dont know.. the answer should be 16/ 17

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

    |dw:1349005592570:dw|

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

    x is the distance the weight has been raised, and y is the horizontal distance, where the rope is attached, to the vertical line passing through the pulley.

  31. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its ok

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

    @bii17 u sure the answer is 16/17

  33. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its correct

  34. bii17
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @sauravshakya yes im sure. that is the answer given in the book

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

    But I got 16/15 @goformit100

  36. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i did the calculation @sauravshakya is correct now

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

    @ganeshie8 if u r free PLZ see this

  38. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @Callisto check it

  39. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    plz

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

    @hartnn can U plz check it

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

    oh i will do it again

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

    |dw:1349007585718:dw|

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

    15 ^2 + x^2 = (33- y)^2

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

    y is the height that the weight rises from the ground. , x is the distance the truck has moved to the left

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

    |dw:1349007886322:dw| @sauravshakya

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

    did you get 16/17?

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

    Oh ya....... @hartnn

  48. hartnn
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    that still doesn't give answer.....

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

    Yep

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

    15 ^2 + x^2 = (33- y)^2 2x *dx/dt = 2 ( 33 - y) * (-dy/dt) x * dx/dt = (33-y) * (-dy/dt) x/ (33-y) * dx/dt = -dy/dt , this works

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

    8 / ( 33 - 16 ) * 2 = 16/17 , x = 8 , that is given, y = 16 by plugging in 15^2 + x^2 = (33-y)^2

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

    the only weird part is the negative sign

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

    @hartnn that gives the answer

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

    oh nevermind, it should be plus

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

    15^2 + x^2 = (33+y)^2

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

    |dw:1349008213306:dw|

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

    |dw:1349008265370:dw|

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

    So,|dw:1349008256578:dw|

  59. hartnn
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes it does, u did it @sauravshakya ! :)

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

    yes that is simpler. the trick is to see that y is constant

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

    |dw:1349008430327:dw|

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

    y = 15,

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

    wait, dh/dt is the rate at which the rope is being pulled

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

    so dh/dt = the rate at which the weight is moving up ? interesting

  65. 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.