Answer:
Let the resultant be
A= ( C2 + B2 )1/2
So
sin = B / ( C2 + B2 )1/2
And
cos = C / ( C2 + B2 )1/2
So the total force is
F = FA + FC + FY
= - k y2 i / c2 + k y2 j / B2 + k y Q ( -cos i + sin j ) / ( C2 + B2 )
F = 0
- k y2 i / C2 + k y2 j / B2 + k y Q ( -sin i + sin j ) / ( L2 + H2 ) = 0
- k y2 i / C2 + k y2 j / B2 + k y Q ( - C / ( C2 + B2 )1/2 i + B/ ( C2+ B )1/2 j ) / ( C2 + B2 )1/2 = 0
Q = - y ( C2 + B )3/2 / C3
k y2 / B2 + k y Q B/ ( C2 + B2 )3/2 = 0
Q = -y ( C2 + b2 )3/2 / B
So equating both " Q " values
- y ( C2 + B2 )3/2 / L3 = - y( C2 + B2 )3/2 / B
so the possible length and the relationship is C= B