1. The vector sum  of real and reactive power is the apparent power. 2. The complex power is the vector sum  of active and reactive power. 3. It calculates the direction of the vector sum  of a set of unit vectors. 4. :Normally it would be a vector sum , but in this case the problem is one dimensional. 5. Electrical impedance is computed as the vector sum  of electrical resistance, capacitive reactance, and inductive reactance. 6. The field around multiple particles is simply the vector sum  of the fields around each individual particle. 7. Note that when vectors or vector fields are involved, a superposition is interpreted as a vector sum . 8. I could guess the vector sum  thing but I have no idea how to calculate magnetic fields. 9. F _ { hkl } is the vector sum  of waves from all atoms within the unit cell. 10. The transition state moves accordingly and the vector sum  of both movements gives the real change in its position.