In which collision momentum is not conserved?

Answered by Douglas Hiatt

In the realm of physics, collisions play a significant role in understanding the behavior of objects when they interact with each other. When two objects collide, there are two important quantities that we consider: momentum and kinetic energy. These quantities help us describe and analyze the motion of objects during and after a collision.

Let’s delve into the concept of momentum before discussing collisions. Momentum is defined as the product of an object’s mass and its velocity. In other words, it is a measure of the motion possessed by an object. Momentum is a vector quantity, meaning it has both magnitude and direction. The principle of momentum conservation states that the total momentum of an isolated system remains constant if no external forces act on it.

Now, coming to collisions, there are two types: elastic and inelastic. In an elastic collision, both momentum and kinetic energy are conserved. This means that the total momentum before the collision is equal to the total momentum after the collision, and the total kinetic energy before the collision is equal to the total kinetic energy after the collision. Elastic collisions are often idealized scenarios where objects do not experience any deformation or energy loss during the collision.

On the other hand, in an inelastic collision, momentum is conserved, but kinetic energy is not. In this type of collision, the total momentum before and after the collision remains the same, but the total kinetic energy changes. Inelastic collisions are characterized by the objects sticking together, deforming, or experiencing energy loss during the collision.

To better understand this concept, let’s consider an everyday situation. Imagine a game of billiards, where two balls collide on a table. When the balls collide elastically, their total momentum is conserved, and they bounce off each other with no loss of energy. However, if the balls collide inelastically, they may stick together after the collision, and some kinetic energy is lost due to deformation or sound production.

Inelastic collisions can also be observed in car accidents. When two cars collide, the total momentum of the system is conserved, but the kinetic energy is not. Some energy is dissipated as heat and sound, and the cars may deform upon impact. This is why crumple zones are designed in cars to absorb some of the impact energy and protect the occupants.

Momentum is not conserved in inelastic collisions, while kinetic energy is conserved in elastic collisions. Inelastic collisions involve objects sticking together, deforming, or experiencing energy loss, whereas elastic collisions involve no loss of energy and objects bouncing off each other. Understanding these concepts allows us to analyze and predict the motion and behavior of objects during collisions, contributing to various fields such as engineering, physics, and even everyday life situations.