Here's why:

* Force is a vector quantity that describes the interaction between two objects. It has both magnitude and direction.

* Movement is a result of a force acting on an object, causing it to change its position.

* The Newton is the standard unit of force in the International System of Units (SI).

Therefore, when we talk about the force that causes movement, we use the unit of Newtons.

Let me know if you have any other questions!