What is the Difference Between Elastic and Perfectly Elastic Collision

The key difference between elastic and perfectly elastic collision is that elastic collision involves an encounter between two bodies with a negligible change in the total kinetic energy, whereas perfectly elastic collision involves no net conversion of kinetic energy into other energy forms.

Elastic and perfectly elastic collision are two chemical concepts in analytical chemistry. These are very closely related concepts.

1. Overview and Key Difference
2. What is Elastic Collision
3. What is Perfectly Elastic Collision
4. Elastic vs Perfectly Elastic Collision in Tabular Form
5. Summary – Elastic vs Perfectly Elastic Collision

What is Elastic Collision?

Elastic collision is the striking of one object against another object with a negligible change in energy. The ideal form of this chemical concept is perfectly elastic collision where there is no net change in total kinetic energy after the striking of two objects. But in real life, there is always a change in the total kinetic energy where some of the energy is converted into another form of energy, but in elastic collisions, in contrast to inelastic collisions, this change in kinetic energy is negligible.

Elastic vs Perfectly Elastic Collision in Tabular Form

Figure 01: Elastic Collision

During the striking of an object with another object, first, the kinetic energy converts completely into potential energy, which is associated with the repulsive or attractive force between two objects. Thereafter, this potential energy converts back to kinetic energy. Typically, the collisions of atoms are elastic.

What is Perfectly Elastic Collision?

A perfectly elastic collision is the physical process of striking one object against another, conserving the kinetic energy of two objects. A perfectly elastic collision is an ideal elastic collision where there is no net conversion of kinetic energy into other energy forms such as heat, noise, or potential energy. But in real life, there are no perfectly elastic collisions because kinetic energy always tends to convert into other energy forms.

Generally, during the collision of small bodies, kinetic energy tends to convert into potential energy first (which is associated with a repulsive force between the two bodies). This happens when particles move against the repulsive force. Then the potential energy tends to convert back to kinetic energy. This happens when particles move with repulsive force. In a perfectly elastic collision, the energy conversions show no net energy loss.

As a real-life example, collisions of atoms are nearly perfectly elastic collisions. For example, Rutherford backscattering is an application of the elastic collision of atoms. Furthermore, molecules in gases or liquids rarely show perfectly elastic collisions. In addition to these, we can approximate perfectly elastic collisions by the interactions of objects such as billiard balls.

What is the Difference Between Elastic and Perfectly Elastic Collision?

Elastic and perfectly elastic collision are two chemical concepts in analytical chemistry. The key difference between elastic and perfectly elastic collision is that elastic collision involves an encounter between two bodies with a negligible change in the total kinetic energy, whereas perfectly elastic collision involves no net conversion of kinetic energy into other energy forms. The collisions of atoms, the collision of balls in billboard game, etc. are examples of elastic collision whereas perfectly elastic collision involve hypothetical collisions that are ideal.

The following table summarizes the difference between elastic and perfectly elastic collision.