Q: I am wondering about i and j notation for vectors. What types of problems require i and j notation? Also, what is the correct format and common errors associated with i and j notation?
A: In general, i, j, k notations are useful in any problems having vector(s) involved. I reviewed the basic operation rules of using i, j, k notations for vectors on the picture. The common errors include sign mistakes, confusion between Dot product and Cross product, etc. In Physics I (Mechanics), the above notations are used popularly in, for example, Force analysis (Application of Newton’s Laws), Work, Rotation (Torque, Angular momentum). In Physics II (Wave/Thermodynamics), the focus is Energy, so the above notations are not used much. In Physics III (Electromagnetism), the above notations are used popularly in, for example, Electric force, Electric field, Electric Potential/Potential Energy, Gauss’s Law, Magnetic Field.
