ANIRUDH VATS
Last Activity: 7 Years ago
SOLUTION: As, the angle between the resultant and vector A is 90.(x)
THEREFORE,
tan x = b sin z / a + b cos z
so, tan90 = b sin z / a + b cos z
1/0 = b sin z / a + b cos z
by reciprocal
0/1 = a + b cos z / b sin z
so, a + b cos z = 0
cos z = – a / b ….1
As, resultant(r) = (a2 + b2 + 2ab cos z) 1/2
so, by putting the value of cos z in this equation from equation 1, we get
resultant(r) = ( b2 - a2)1/2
NOW A.T.Q., WE PUT THE RESULTANT VALUE IN THIS EQUATION,
b / 2 = (b2 – a2)1/2
squaring both sides, we get
(b2 / 4) – b2 = – a2
therefore,
a = (root3 / 2) * b
so,
a/b = root3 / 2
PUT THIS IN EQUATION 1, WE GET
cos z = – ROOT3 / 2
THEREFORE,
Z = 1500