Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
woleraymond
Group Title
The resultant of vectors A and B has a magnitude of 20units. A has a magnitude of 8units and the angle between A and B is 40 degrees. calculate the magnitude of B?
 2 years ago
 2 years ago
woleraymond Group Title
The resultant of vectors A and B has a magnitude of 20units. A has a magnitude of 8units and the angle between A and B is 40 degrees. calculate the magnitude of B?
 2 years ago
 2 years ago

This Question is Closed

rs32623 Group TitleBest ResponseYou've already chosen the best response.0
\[(8^{2}+B^{2}+2*8*B*Cos40)=20^{2}\] Can you proceed from here finding the value of B?
 2 years ago

VincentLyon.Fr Group TitleBest ResponseYou've already chosen the best response.1
Use ruler and compass. You will get the value you need, then use geometry. Either resolve your vectors or work out magnitude directly using following link: http://en.wikipedia.org/wiki/Law_of_cosines
 2 years ago

woleraymond Group TitleBest ResponseYou've already chosen the best response.0
@rs32623 which formula are u using?
 2 years ago

VincentLyon.Fr Group TitleBest ResponseYou've already chosen the best response.1
He is using the Law of cosines I mentioned above.
 2 years ago

rs32623 Group TitleBest ResponseYou've already chosen the best response.0
i am using the formula for the resultant of two vectors A & B having magnitude A & B & angle between them if theta then the resultant is R=sqrt(A^2+B^2+2*A*B*Costheta)
 2 years ago

woleraymond Group TitleBest ResponseYou've already chosen the best response.0
i think the preferred solution is Resultant = \[sqrt{A^2 + B^2}\]
 2 years ago

VincentLyon.Fr Group TitleBest ResponseYou've already chosen the best response.1
But this is true if and only if vectors A and B are at right angles.
 2 years ago

woleraymond Group TitleBest ResponseYou've already chosen the best response.0
if it is cosine rule then it should be R=sqrt(A^2+B^22*A*B*Costheta)....do you guys agree....@VincentLyon.Fr @rs32623
 2 years ago

VincentLyon.Fr Group TitleBest ResponseYou've already chosen the best response.1
You should end up with B = 13.20
 2 years 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.