⇒ Momentum is defined as mass multiplied by velocity: p = mv

⇒ Momentum is a vector quantity

⇒ Newton's second law of motion states that resultant force is the mass multiplied by the acceleration: F = ma

⇒ Newton's third law of motion states that to every force there is an equal and opposity force. Such paired forces are of the same type, act along the same line, and act on separate bodies

⇒ Acceleration is the change of velocity divided by time

⇒ The principle of conservation of energy states that energy cannot be created or destroyed, but it can be transferred from one type of energy to another

⇒ Momentum is a useful quantity in physics because the amount of momentum in a system always remains the same provided no external forces act on that system

⇒ This system allows us to predict what will happen in a collision or an explosion

⇒ For example, when a firework explodes, chemical potential energy is transferred to thermal energy, light energy, and kinetic energy of the exploding fragments

• However, during the explosion, the momentum remains the same

⇒ Momentum is a vector quantity; the momentum of a fragment travelling in one direction is balanced by the momentum of a fragment travelling in the opposite direction

⇒ Also see our notes on:

• Momentum and Impulse
• Conservation of Linear Momentum
• Momentum and Energy
• Elastic and Inelastic Collisions