If two forces P and Q are such that |P + Q| = |P - Q|, then the angle between P and Q is:

Explanation

To solve this problem, use the properties of vector addition and subtraction. When |P + Q| = |P - Q|, the vectors P and Q must be perpendicular to each other. This occurs when the angle between them is 90 degrees.In terms of vector mathematics, this situation implies:P^2 + Q^2 + 2PQcos(x) = P^2 + Q^2 - 2PQcos(x)Solving this for x gives 4PQcos(x) = 0, which simplifies to cos(x) = 0. Therefore, x = 90 degrees.Options 0 degrees and 180 degrees would result in the magnitudes being clearly unequal due to vector alignment or opposition, respectively. Option 30 degrees would also not satisfy the condition of equal magnitudes.