Question

Find the angle between two equal forces P,if there resultant is P.

Answer 1

Answer:

Angle between the 2 equal forces = 120°

                                                         =2π/3 rad

Explanation:

We know that, if A and B are 2 vectors with angle θ between them ,

then the resultant of A and B is

Resultant = √ (A² + B² + 2ABcosθ)

Here it is given that,

A = B = Resultant = P

θ = ?

Putting these values in

P = √ (P² + P² + 2×P×Pcosθ)

Squaring both sides we get

P² = 2P² + 2P²cosθ

2P²cosθ = P² - 2P²

2P²cosθ = -P²

cosθ = -1/2

θ = 120°

θ = 2π/3 RAD