# Vectors

A vector is used in geometry and physics to represent physical quantities that have both magnitude and direction. Think of physical quantities like velocity, movement, acceleration and force.

### What is a vector?

What is a vector? A vector is often used in geometry and physics to represent physical quantities that have both magnitude and direction. Think of physical quantities like speed, movement, acceleration and force! In this video you learn vector notation, vector addition and multiplication with a scalar.

### Length of a vector

What is the length of a vector? A vector is often used in geometry and physics to represent physical quantities that have both magnitude and direction. In this video you will learn how to calculate the length of a vector and the distance between two vectors.

### Dot-product

How can you take the product of two physical quantities using vectors? In this video you learn to calculate the dot product in a algebraic way and learn the properties of the dot product.

### Orthogonal projections - part 1

How can you decompose a physical quantity like force in perpendicular forces? You can use the orthogonal projection of a vector! In this video you learn how!

### Orthogonal projections - part 2

How can you calculate orthogonal projections and scalar projections of vectors? This video shows you how!

### Cross product

How to multiply vectors? You can multiply vectors and find a perpendicular vector by using the cross product. This video shows you the Amsterdam method to calculate the cross product and teaches you the right hand rule to determine the direction of the resulting vector.

### Cross product applications

The cross product of vectors has important applications in physics and mathematics. This video shows how you to calculate the volume of a parallelepiped and to calculate torque using the cross product.

### Lines and planes

You can use a vector equation to describe a line or a plane. This video shows you how to do this!