C2 Force and Motion

• The first law of motion, also known as the law of inertia, states that an object at rest will stay at rest and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force.
• Newton's third law of motion states that for every action, there is a reaction of equal magnitude in opposing direction.
• The second law of motion states a larger net force acting on an object causes a larger acceleration, and objects with larger mass require more force to accelerate.

  Force = Mass x Acceleration
• Inertia is the natural tendency of a body of mass to resist any change to its current state of rest or motion.
• The S.I unit for mass is kilogram (kg).
• Displacement is the shortest distance travelled between initial position and the final position in a specific direction.
• Free fall is the falling of a body in vacuum due to the gravitational force.
• A vector quantity has both magnitude and direction while scalar quantities have only magnitude.
• Acceleration is the rate of change of velocity.