Practical 2 - Laws of Motion Part B Aim To introduce concepts related to forces including vectors, the line of action of a force and adding and subtracting forces. To

introduce the concept of friction and the factors that affect the magnitude of friction forces. Friction is the resistance to movement between two surfaces in contact. The direction of the friction force is always opposite to the motion between the two surfaces. Friction is dependent on the surfaces involved, the applied force (perpendicular to the surface; a "normal" force) and whether the surfaces are stationary or moving.