Friction is a type of force so it is measured in ______________. Friction is the resistance of one s__________ sliding over another. It occurs because most surfaces small _______ which grip objects. Friction can be over come with l_____________ which uses liquids to fill in these small gaps. Objects can also have some intermolecular ____________ with each other increasing the f__________. Friction always acts in the ____________ direction to an object’s movement. This means it s______________ and the speed ____________. If we are describing a car moving forwards, the _________ is the force that helps the car move forwards. The f______________ and a___ __________ are forces that act against the car and d________________ its speed