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# Is it necessary to use unit vectors in physics?

### 5 Answers

- Anonymous2 months ago
yeahhhh : several units are vectors !!!

- nebLv 72 months ago
No, but ....

If you get into more advanced physics, you will find unit vectors are replaced by the more general concept of basis vectors. Basis vectors are those vectors by which the components of other vectors are defined. Those basis vectors need not be unit vectors, nor do they even have to be orthogonal, nor do the same basis vectors have to the same everywhere. They can change with position in space and time. They do have to be linearly independent and span the vector space.

Unit vectors are just a simple choice of basis vectors for simple problems. Generally they align with the coordinate system and are chosen to have unit magnitude. Just makes things easier and more intuitive.

I should add that there is no need at all for basis vectors. Other vectors don’t need their components defined with respect to basis vectors. It’s only when you want to compute components with respect to a coordinate basis where you will need them.

- az_lenderLv 72 months ago
Of course not, there are other systems of indicating direction. But you'll find that many people are using unit vectors, so you'll have a hard time understanding conversations that involve them, if you don't know what they mean.

- MorningfoxLv 72 months ago
Only if you want to understand the equations. It's like using meters, or kilograms, or any other "unit" thing.