- #1
warfreak131
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Homework Statement
Given vectors [tex]\bold{\vec{A}}=-4.8\bold{\hat{i}}+6.8\bold{\hat{j}}[/tex] and [tex]\bold{\vec{B}}=9.6\bold{\hat{i}}+6.7\bold{\hat{j}}[/tex], determine the vector [tex]\bold{\vec{C}}[/tex] that lies in the xy plane perpendicular to [tex]\bold{\vec{B}}[/tex] whose dot product with [tex]\bold{\vec{A}}[/tex] is 20.0
Homework Equations
[tex]\theta_{\vec{B}}=\arctan{\frac{6.7}{9.6}}=35 degrees[/tex]
Dot prod. of perpendicular vectors = 0, therefore
[tex]\vec{B}{\cdot}\vec{C}=B_{i}C_{i}+B_{j}C_{j}=0[/tex]
[tex]\vec{B}{\cdot}\vec{C}=9.6C_{i}+6.7C_{j}=0[/tex]
[tex]\vec{A}{\cdot}\vec{C}=A_{i}C_{i}+A_{j}C_{j}=20[/tex]
[tex]\vec{A}{\cdot}\vec{C}=-4.8C_{i}+6.8C_{j}=20[/tex]
The Attempt at a Solution
I'm not sure where to start, that's why I'm here :)