State the principle of conservation of linear momentum and distinguish between elastic and inelastic collision
The principle of conservation of linear momentum states that the total momentum of a closed system remains constant if no external forces act on it. In other words, the momentum before an event (such as a collision) is equal to the momentum after the event.
An elastic collision is one in which the total kinetic energy of the system is conserved. This means that after the collision, the objects involved retain the same amount of kinetic energy as they had before the collision. In math terms, the momentum and velocity change for each object, but the total kinetic energy of the system is the same before and after the collision.
An inelastic collision, on the other hand, is one in which the total kinetic energy is not conserved. After the collision, some of the kinetic energy may be converted into other forms of energy, such as heat or sound. In an inelastic collision, the momentum and velocity do change for each object, but the total kinetic energy of the system is not the same before and after the collision. In fact, the total kinetic energy will always be less after an inelastic collision.