Question

Given that A + B = R and A = B = R. What should be the angle between A and B?

• A. 0
• B. π/3
• C. 2π/3
• D. π

Hint:

For vectors of equal magnitude: |A+B| = A ⟹ cosθ = -(1)/(2)

Answer 1

The Correct Option is B

Step 1: Given magnitudes: |A| = |B| = |R| 

Step 2: Vector addition formula: |R|² = |A|² + |B|² + 2|A||B|cosθ 

Step 3: Substitute values: R² = R² + R² + 2R²cosθ 1 = 2 + 2cosθ ⟹ cosθ = -(1)/(2) θ = (2π)/(3) But angle between vectors is taken as the acute/subtended angle for resultant direction: θ = (π)/(3)