Final answer:
Collisions occur when two or more objects come into contact with each other, resulting in a transfer of momentum and energy. There are two main types of collisions: elastic collisions and inelastic collisions.
Step-by-step explanation:
Collisions occur when two or more objects come into contact with each other, resulting in a transfer of momentum and energy. There are two main types of collisions: elastic collisions and inelastic collisions.
In an elastic collision, both momentum and kinetic energy are conserved. This means that the total momentum and the total kinetic energy of the system before and after the collision are the same. A common example of an elastic collision is a billiard ball collision, where the balls bounce off each other.
On the other hand, in an inelastic collision, kinetic energy is not conserved. Some or all of the kinetic energy is transformed into other forms of energy, such as heat or sound. In inelastic collisions, the objects may stick together after the collision, as seen in an explosion, or they may deform and bounce off each other, but with reduced velocity.