Two forces of equal magnitude simultaneously act at a point. It is observed that the resultant force is equal in magnitude to the individual forces. Which of the following statements is/are correct?
I. The angle between one of the individual forces and the resultant force is π/3.
II. The angle between the individual forces is 2π/3.
Select the answer using the code given below.

Question

Accepted Answer

Both I and II. When two forces of equal magnitude F act at a point with angle θ between them, the resultant has magnitude R = 2F cos(θ/2). For R = F, we get cos(θ/2) = 1/2, which gives θ/2 = π/3, so θ = 2π/3 (120°). This confirms statement II. For statement I, by symmetry, the resultant bisects the angle between the two equal forces, so it makes angle θ/2 = π/3 (60°) with each individual force. Therefore, both statements I and II are correct.

Explanation

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