Question

Two vector, both equal in magnitude, have their resultant equal in magnitude of the either. Find the
angle between the two vectors.​

Answer 1

Answer:

let R , Q are two vector which magnitude is equal also resultant of it also equal to either

e.g | R | = | Q |

and resultant = R + Q

magnitude of resulatant = | R | = | Q|

so, | R | = | R + Q |

| R | = √( | R|² + | Q|² +2|R | |Q| cos∅)

take square of both sides

R² = R² + Q² + 2|R| |Q| cos∅

put | R| =|Q|

R² = R² + R² +2R² cos∅

cos∅ = -1/2

∅ = 2π/3

Explanation: