Question

The vector that must be added to the vector i-3j+2k and 3i+6j-7k so that the resultant vector is a unit vector along the y-axis is?

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Answer 1

We have,

A=i−3j+2k and B=3i+6j−7k

So, here A+B+C=j .... (j is the unit vector along the y-axis and Cis the resultant vector)

So, A+B=4i+3j−5k.−2

So, According the subst rule (2) in( 1):

4i+3j−5k+C=j

C=j−(4i+3j−5k)

=j−4i−3j+5k

=−4i−2j+5k

Thus, −4i−2j+5k is the vector which must be added so that the resultant is a unit vector along the y-direction.