Register to reply

Multiplication of vector problem

by Adrianw2
Tags: vectors
Share this thread:
Adrianw2
#1
Oct10-07, 11:51 AM
P: 14
1. The problem statement, all variables and given/known data
Let B = 5.00m at 60 degrees. Let C have the same magnitude as A and a direction angle greater than that of A by 25.0 degrees. Let A*B = 30.0 m^2 and B*C = 35.0 m2. Find A.


2. Relevant equations
Pythagoras maybe.


3. The attempt at a solution
Well, if A*B is 30 m^2, and B is 5.00m, then shouldn't A = 6.0 m? However, I don't think it's that easy, so I made the right angle triangle with B (5.0m) as the hypotenuse at 6 meters above the horizontal, and got 4.33m as the opposite and 2.5m as the adjacent. Am I going to be calculating areas of triangles? I'm not really sure where to go from there.

Thanks
Phys.Org News Partner Science news on Phys.org
World's largest solar boat on Greek prehistoric mission
Google searches hold key to future market crashes
Mineral magic? Common mineral capable of making and breaking bonds
Hootenanny
#2
Oct10-07, 12:04 PM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,781
I'm assuming the astericks denote the scalar product? I think your going to have to set up a system of simulatenous equations.
Adrianw2
#3
Oct10-07, 12:11 PM
P: 14
Yeah, the astericks are actually a dot, so it may have something to do with the dot product where it's AxBx + AyBy or something along those lines.

Hootenanny
#4
Oct10-07, 12:16 PM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,781
Multiplication of vector problem

Quote Quote by Adrianw2 View Post
Yeah, the astericks are actually a dot, so it may have something to do with the dot product where it's AxBx + AyBy or something along those lines.
I suggest you write out two equations using [itex]\theta[/itex] to denote the unknown angle.


Register to reply

Related Discussions
Expressing cartesian unit vectors in terms of spherical unit vectors General Math 9
About polar vectors and pseudo vectors Classical Physics 10
Position Vectors, Velocity Vectors, and Acceleration Vectors Introductory Physics Homework 3
PROOF: Independent vectors and spanning vectors Linear & Abstract Algebra 8
Learning vectors: the dot product of vectors General Math 5