How to compare physical vectors and directional scalars Do you ignore the direction when comparing the size of vectors? For directional scalars, such as acceleration 1 and - 2, which is larger? Do you want to compare absolute values?

How to compare physical vectors and directional scalars Do you ignore the direction when comparing the size of vectors? For directional scalars, such as acceleration 1 and - 2, which is larger? Do you want to compare absolute values?

In addition, acceleration is not a scalar with direction, it is also a vector. It is a one-dimensional vector without "scalar with direction". Any quantity with direction and size is called a vector, and scalar is a quantity without direction. Acceleration - 2 is large, because | - 2 | = 2, "module" is simply the length of this vector, The length of one-dimensional vector is the absolute value of coordinates, that is √ x ^ 2 = | x |. If it is two-dimensional, the length of this vector is: √ (x ^ 2 + y ^ 2), (in the plane rectangular coordinate system, which is the same as the mathematical derivation, X, y are the coordinates of vectors). Similarly, in three-dimensional, it is: √ (x ^ 2 + y ^ 2 + Z ^ 2), x, y, Z are the coordinates of space vectors, in the space rectangular coordinate system. In the theory of relativity, there are four-dimensional vectors, The length of vector is: √ (x ^ 2 + y ^ 2 + Z ^ 2 + (ICT) ^ 2), where I is the imaginary unit and C is the speed of light. Vector is the vector in mathematics. Comparing their size means comparing their length, that is, comparing their size without direction