Question

Two equal vectors have a resultant equal to either of them, then the angle between them will be

• A. 120${}^{∘}$
• B. 110${}^{∘}$
• C. 60${}^{∘}$
• D. 150${}^{∘}$

Answer 1

Answer: (A)

It is given that two vectors have a resultant equal to either of them. hence
$F^2=F^2+F^2+2F^{2}cosθ$
$1=(1+cosθ)$
or $30mmθ=120^{∘}$