Dabour Hub EGEgyptian Curriculum 2026/2027
Geometry of 3D Vectors and Scalar/Cross Product Physics

Geometry of 3D Vectors and Scalar/Cross Product Physics

Point 2 of 7 — Lesson 1: Three-Dimensional Cartesian Coordinates and Vector OperationsQuestion bank: 9 questions (5 with pictures)

03 Geometry of 3D Vectors and Scalar/Cross Product Physics

  • In three dimensions, any vector is represented by components A⃗=Axi^+Ayj^+Azk^.
  • Direction cosines satisfy the identity cos⁡2α+cos⁡2β+cos⁡2γ=1.- Dot Product: A⃗⋅B⃗=AxBx+AyBy+AzBz.
  • It calculates the angle between vectors cos⁡θ=A⃗⋅B⃗∣∣A⃗∣∣∣∣B⃗∣∣ and the scalar projection of A⃗ onto B⃗ (=A⃗⋅u^B).
  • Two non-zero vectors are perpendicular if and only if A⃗⋅B⃗=0.- Cross Product: A⃗×B⃗=∣i^j^k^AxAyAzBxByBz∣.
  • Its magnitude ∣∣A⃗×B⃗∣∣ geometrically represents the AREA of the parallelogram spanned by A⃗ and B⃗.
  • The triangle area is half of this magnitude.

📝 Question bank for this point

9 questions linked to this point only, 5 of them with pictures.