Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 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
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

MuH4hA Group TitleBest ResponseYou've already chosen the best response.1
By you getting a(t)xh(t), you mean you keep getting\[a \times h =  G\,M\, \dot u\] ???
 one year ago

Shadowys Group TitleBest ResponseYou've already chosen the best response.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

MuH4hA Group TitleBest ResponseYou've already chosen the best response.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

Shadowys Group TitleBest ResponseYou've already chosen the best response.0
so i guess the book's wrong...
 one year ago

MuH4hA Group TitleBest ResponseYou've already chosen the best response.1
Why would it be wrong? What does the book say? o.O
 one year ago

Shadowys Group TitleBest ResponseYou've already chosen the best response.0
show that (v(t)xh(t))'=GMu(t) this is the original question... lol
 one year ago

MuH4hA Group TitleBest ResponseYou've already chosen the best response.1
Well .. that is what you showed, isn't it? (sry, I don't see your problem ... please elaborate)
 one year ago

Shadowys Group TitleBest ResponseYou've already chosen the best response.0
I'm trying to seek confirmation that the book is missing a particular ' sign. :P it seems so. lol thanks.
 one year ago
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
 Engagement 19 Mad Hatter
 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.