Resultant force from vector addition of two perpendicular forces

Steps:

• Identify the two forces as 3 N and 4 N acting at right angles, based on typical diagram setup.
• Resolve into components: one along x-axis (3 N), one along y-axis (4 N).
• Calculate magnitude using Pythagorean theorem: √(3² + 4²) = √(9 + 16) = √25 = 5 N.
• Confirm no other components or angles affect the calculation.

Why C is correct:

• The magnitude of the resultant vector for perpendicular forces follows the Pythagorean theorem: R = √(F₁² + F₂²).

Why the others are wrong:

• A: Incorrectly assumes subtraction of forces, ignoring vector addition.
• B: Wrongly averages the magnitudes instead of using vector sum.
• D: Mistakenly adds forces scalarly, disregarding direction.

Final answer: C