1. Forces are defined by strength but not direction
2. Forces are defined by direction but not strength
3. Forces are defined by but strength and direction
4. Forces act only on objects that are in contact
Force is defined a push or a pull applied on an object.
It is defined by both strength and direction. This is because force is an example of a vector quantity.
A vector quantity is a quantity with both magnitude and direction.
In this case, force is a quantity that has both magnitude and direction, such that the strength of a force is the magnitude of the force while the direction shows direction of the application of force.
Hence, force has to be defined using both magnitude and direction.
