Posted by Mat on .
We have a problem in AP Physics that we just can't get. It has to do with vector addition. The problem is:
If aA+bB+C=0, find the magnitudes of a and b.
*A, B, and C are vectors*
*i and j are unite vectors*
A=(6.0i8.0j)units
B=(8.0i+3.0j)units
C=(26.0i19.0j)units
How is that possible without a second equation for the relationship between a and b? You can't do substitution or anything. And by lokking at it for an extended period of time, we found that a=5 and b=7 works, but we don't know how to find that using algebra.
help??

Science 
bobpursley,
You have a second equation. Do the i, j separately..
i:
6a 8b+26=0
j
a8+3b19=0
solve for a,b