Question

If the resultant of two forces is half of one of the vectors, then what will be the angle between the two forces?
@ 28.90° b)41.40° © 138.6° d) 151.04°​

Answer 1

R^2= A^2+B^2+2ABcosx= 2A^2+2A^2cosx

(A/2)^2 = 2A^2(1+ cosx)

1/8= 1+cosx

-7/8= cosx=

7/8= cos{180°- X)

(180°-x) = 29°

X= 151°

option d is correct answer