A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

idku

  • one year ago

math-based-physics question.

  • This Question is Closed
  1. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    o goody

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

    Julie throws a ball to her friend Sarah. The ball leaves Julie's hand a distance 1.5 meters above the ground with an initial speed of 11 m/s at an angle 44 degrees; with respect to the horizontal. Sarah catches the ball 1.5 meters above the ground. ------------------------------------------------------------------------- 2) What is the vertical component of the ball’s velocity right before Sarah catches it? 3) What is the time the ball is in the air?

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

    I attempted (for question # 2) \(11\sin(44)\approx7.6\)m/s but it doesn't work when I enter it in my pracice thingy.

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

    The image would be this: http://i.imgur.com/TLF8qrM.png

  5. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yep okay

  6. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    a complete parabollic motion completed in this throw okayq

  7. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so the same vertical speed it started out with is the same speed it ended with

  8. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    |dw:1441330388180:dw|

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

    Yes, so I tried 11sin(44) but it didn't work....

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

    (well, I entered 7.64 approximation)

  11. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    its downward now so

  12. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    it will be negative -11*sin(44)

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

    Oh, cool. Thanks, and how do I figure question #3?

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

    3) What is the time the ball is in the air?

  15. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    okay now we dont really care about the horizontal component of the veloicty that is not going to determine how long the ball will stay up in the air

  16. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    What we need to worry about is the veloicty in Y and the acceleration in Y

  17. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    now lets break the problem into 2 symmetric parts, the time it takes the ball to go up, and then the time it takes the ball once its all the way up to fall back down will be the same

  18. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    this is something you should prove to yourself when u have time

  19. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so what we will do is figure out the time he takes from |dw:1441330648992:dw|

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

    well, considering any vertex of (h,k) the vertical distance from (h,k) to (h,k+a) and the vertical distance from (h,k) to (h,k-a) are same. ik that:)

  21. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    okay

  22. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    what is the speed at the top of the arc?

  23. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    the velocity / speed of the ball

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

    I am just very unfamiliar with the formulas I have to apply at each time.

  25. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    no formulas needed

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

    lol (?)

  27. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    what happens to the velocity at the very top

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

    it is 0

  29. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    right

  30. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so we started with 11sin(44)m/s and went to 0 m/s now acecleration tells you how velocity changes wrt to time\ we have a constant acceleration of 9.8m/s^2 "9.8 m/s /s" we change 9.8m/s(speed) /s(per second)

  31. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so if we went from / 11 sin(44) m/s to 0 m/s how many second would that have took if every second we lose 9.8m/s

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

    11sin(44)/9.81 seconds

  33. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    good :)

  34. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    now that is the time for half the motion right

  35. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so multiply that time by 2 and ur done

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

    I am really not that good to do logical conclusions like this on my own though. I think that practicing formulas at first and then comprehending to an extent of a logic would be better for me..... Yes, multiply that by 2, so we got 2sin(44) (m/s) ------------ 9.81 (m/s^2) and our units are seconds as well....

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

    times 2, because we go from max vel to 0 velocity twice.

  38. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    2 * 11 *sin(44)/9.81

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

    1.56 seconds

  40. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    probably right

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

    Wolfram is always right:D

  42. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    :)

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

    And how would I briefly go about the distance between the two girls?

  44. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    okay so we know the time it was up in the air

  45. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    now for that same time, it was constatly moving horizontally with that horizontal speed given 11 cos(44)

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

    distance = time 5 velocity ?

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

    oh, 5 was supposed to be ×

  48. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes thats right

  49. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    by definition speed is the change in distance per time unit m/s

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

    distance = 1.56 • 11cos(44) <-- that is our horizontal velocity ^ | the time for vertical and horizontal is same.....

  51. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes

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

    1.56s • 11cos(44)(m/s) and units work too

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

    12.34

  54. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    oh btw, you know how to you said youd rather pratice formulas to solve this, you should forget that way of thinking, it might even help you getting marks as far as highschool goes... but you will just be memorizing formulas and not understanding

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

    \[\Delta x = v_{i_x}t + \frac{1}{2}gt^2\] can this work too? just wondering.

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

    a=0 in horizontal force

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

    because no gravity

  58. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    IF you want to do good in college, and get further in physics and other related stuff, you are better of understanding and trying to do this more logically

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

    so just v•t

  60. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    eventually those people that are memorizing wont be able to solve the tougher problems

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

    I am making sense out of it.... my prof is a good person but by no means can he be a teacher ... -:( tnx for helping me with it. I am kind of bad it (comparing to other subjects), but tnx!

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

    dan is absolutely right

  63. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    dont worry it takes a while to get comfortable in physics

  64. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    i had one highschool teacher that gave us good advice, he said make sure you can picture the problem

  65. dan815
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    always do your best to picture the problems, really understand the question, understanding the questions is sometimes the most difficult part

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

    Jhanny it is the teacher, I promise....

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

    yes, understanding is best, because it is the only way to put it into memory

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

    Many people do not like their physics professors, but its really in understanding what youre learning thats weighing you down, not the professor

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

    I will have some more questions, and entire night to work on (waiting for friday 3pm after physics to chill). I have to ask more and do it..... sorry that I am stopping the conversation like this.

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

    No, he doesn't explain he just derives formulas from formulas....

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

    good luck, bye, apologize.

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

    np :)

  73. 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.