**Vectors are very important in Physics and especially in physics problems.**Why?

**Because many physical quantities,**such as velocity, acceleration, force, electric field, magnetic field, and others

**are vectors.**

**Vectors carry the information about magnitude and direction of physical quantity.**

**For example,**we know the vector of velocity. It means that we know the direction of the motion and the magnitude of velocity (speed).

## Properties of vectors

## * two vectors are equal if they are equal in both magnitude and direction:

##
*** addition of two vectors:**

*** multiplication by a number**

Vector (where is the positive number) has the same direction as vector , but its length is times larger then the length of vector .

Vector (where is the negative number) has the direction opposite to the direction of vector , but its length is times larger then the length of vector

*** scalar (dot) product**

is a scalar (not vector) =

**If the vectors are**

**orthogonal**

**then the scalar product is 0**

*** vector product**

is a

**VECTOR**, the magnitude of which is
Vector is orthogonal to the plane formed by vectors and .

**If two vectors have the**

**same direction**

**then vector product is 0**