Question

if vector "a"=3i+4j and vector "b"=7i+24j,then find the vector which has the same magnitude as "b" and parallel to "a"

Answer 1

the vector is 15i+2oj

Answer 2

sir can u tell me how

Answer 3

i did this question by a hit and trial method
the magnitude of b is 25 ,
now ,any parllel vector can be obtained by just multiplying that vector with some number like a=3i+4j is parallel to 6i+8j here i multiplied by 2 ,In similar way if u multiply by 5 this gives the parallel vector to a with magnitude 25

Answer 4

turn <a> into a unit vector and then multiply it by the magnitude of <b>

Answer 5

the magnitude of a vector is just the pythag thrm:

b <7,24>

|b| = sqrt(625) = 25

a = <3,4>

|a| = sqrt(25) = 5

unit a = (1/|a|) <3,4>
= <3/5, 4/5>

unit a * |b| = deisred results

25 (3/5, 4/5 ) = <15,20>