Question

The sum of two forces p and q is r such that p=r. The angle theta that the resultant of 2p and q will make with q is?

Answer 1

90°

Explanation:

see the image attached with the answer,

Now,

|vector P + vector Q| = |vector P|

P² + Q²+ 2PQcosθ = P²

= Q+ 2P cos θ = 0

cos θ = -Q/2P

see second image 2.

Now, tan α = 2Psin θ /2P cosθ + Q = ∞    ∵{2Pcosθ + Q = 0}

α = 90°

Answer 2

Answer:

The angle between 2p vector and q vector is 90°.