Question

Two forces vector F₁ and vector F₂ are acting at right angles to each other. Then their resultant is 

1. F₁ + F₂
2. √(F₁² + F₂²)
3. √ (F₁² - F₂²)
4. (F₁ + F₂)/2

Answer 1

Answer: 2. √(F₁² + F₂²)

Explanation :

Resultant of 2 vectors, R = √(F₁² + F₂² + 2F₁F₂cos θ)

∵  Vectors are acting at 90° , cos θ  = 0. 

⇒ R =  √ (F₁² + F₂²)