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

Shadowys Group Title

r(t) is a position vector. v(t) is r'(t) or the velocity vector, and a(t) is the acceleration vector. u(t) is a unit r(t) vector. Also, F(t)=ma(t)=-GMmu(t)/r^2 h(t)= r(t) x v(t)=r^2 u(t) x u'(t) show that (v(t)xh(t))'=-GMu'(t) somehow I keep getting GMu(t) or (a(t)xh(t)) instead...

  • one year ago
  • one year ago

  • This Question is Closed
  1. MuH4hA Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    By you getting a(t)xh(t), you mean you keep getting\[a \times h = - G\,M\, \dot u\] ???

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

    wait sorry, it's reversed. the question wants (v(t)xh(t))'=GMu˙but i keep getting (a(t)xh(t))=-GMu' instead

    • one year ago
  3. MuH4hA Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Well, then you are fine, cause\[(v \times h)' = v' \times h = a \times h =- G\, M\, \dot u\]That's because you showed earlier, that h is constant (second law of Kepler) and thus the derivative of it is 0.

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

    so i guess the book's wrong...

    • one year ago
  5. MuH4hA Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Why would it be wrong? What does the book say? o.O

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

    show that (v(t)xh(t))'=GMu(t) this is the original question... lol

    • one year ago
  7. MuH4hA Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Well .. that is what you showed, isn't it? (sry, I don't see your problem ... please elaborate)

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

    I'm trying to seek confirmation that the book is missing a particular ' sign. :P it seems so. lol thanks.

    • 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.