JEE Main Physics question

Physics Motion in a Plane JEE Main

Two forces of magnitude F each have a resultant of the same magnitude F. The angle between the two forces is

(A)45°
(B)120°Correct
(C)150°
(D)60°

Answer: (B)

Solution

R² = F² + F² + 2F²cosθ = 2F²(1+cosθ). Setting R = F: F² = 2F²(1+cosθ) ⟹ 1+cosθ = 1/2 ⟹ cosθ = −1/2 ⟹ θ = 120°.

Question ID VK-153300