Elastic Collision - Definition, Examples, Difference Between Elastic and Inelastic Collision, FAQs

In an elastic collision, both momentum and kinetic energy are conserved as two objects collide and then separate without any loss of energy to sound, heat, or deformation. This type of collision is ideal and often occurs in systems with low friction, like gas molecules in a container.

In the article, we are going to learn what is a Collision, types of collision, Elastic collision, Inelastic collision, the difference between Elastic and Inelastic collision, elastic collision examples.

What is Collision?

Two things collide when they come into direct contact with each other, and there is a change in their momentum and energy that event is called as Collision.

It occurs when two or more bodies exert forces on one other in a relatively short period of time.

Types Of Collision

Collison can be furthur dicided into two types, i.e., Elastic and Inelastic Collision. Now let's understand these types in detail.

Define Elastic Collision

We often wonders that What is elastic collision in Physics? Answer to that question is- "A fully elastic collision occurs when two bodies collide with each other without losing any Kinetic energy." In this type of collision no Kinetic energy is lost. Hence we can say that, in an elastic collision, both momentum and kinetic energy are conserved.

Example of Elastic Collision

Two Biliard balls colliding with each other is an example of a perfectly elastic collision.
There is no change in net kinetic energy when you throw a ball on the ground and it bounces back to your hand, hence it is an elastic collision.

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This Story also Contains

1. What is Collision?
2. Define Elastic Collision
3. What Is Inelastic Collision?
4. Difference between Elastic and Inelastic Collision

Characteristics of Elastic Collision:

• The linear momentum of an object is conserved in an elastic collision.
• The object's overall energy is conserved.
• The kinetic energy of the system is also conserved.
• During an elastic collision, conservative forces are at work.
• In an elastic collision, the mechanical energy is not transferred to heat.

Super elastic collision

A superelastic collision occurs when potential energy is converted into kinetic energy, In a superelastic collision, the final kinetic energy of the system is more than the initial kinetic energy.

Examples of Super Elastic Collisio

When a firework blasts in mid –air it just disintegrates into many particles that go in various directions. This explosion push the chemical energy stored which in turn raises the kinetic energy of the fragments.

Elastic Collision Formula

In an elastic collision, both momentum and kinetic energy are conserved.

For two colliding objects with masses $m_1$ and $m_2$, and initial velocities $u_1$ and $u_2$, the final velocities $v_1$ and $v_2$ after the collision can be given by:
1. Conservation of Momentum:

$$
m_1 u_1+m_2 u_2=m_1 v_1+m_2 v_2
$$

2. Conservation of Kinetic Energy:

$$
\frac{1}{2} m_1 u_1^2+\frac{1}{2} m_2 u_2^2=\frac{1}{2} m_1 v_1^2+\frac{1}{2} m_2 v_2^2
$$

Using these equations, we can solve for the final velocities of the two objects as follows:
- Final Velocity of $m_1$ :

$$
v_1=\frac{\left(m_1-m_2\right) u_1+2 m_2 u_2}{m_1+m_2}
$$

- Final Velocity of $m_2$ :

$$
v_2=\frac{\left(m_2-m_1\right) u_2+2 m_1 u_1}{m_1+m_2}
$$

What Is Inelastic Collision?

Inelastic collision occurs when two objects collide together and they lose their initial kinetic energy. This lost kinetic energy of the colliding objects is used to produce another form of energy which includes heat, and sound energy, and also can deform the object permanently.

Example of Inelastic Collision

When two cars collide with each other (accident), large amount of Kinetic energy is converted into heat energy and sound energy, and the bending of the metal of the cars.

Characteristics of Inelastic Collision:

• Momentum is conserved in an inelastic collision.
• The complete amount of energy is preserved.
• The kinetic energy of the system is not preserved.
• An inelastic collision involves non-conservative forces.

Inelastic Collision Formula

For a perfectly inelastic collision (where the objects stick together after collision), the final velocity $v$ of the combined mass after collision is given by:
1. Conservation of Momentum:

$$
m_1 u_1+m_2 u_2=\left(m_1+m_2\right) v
$$

Solving for $v$, we get:

$$
v=\frac{m_1 u_1+m_2 u_2}{m_1+m_2}
$$

Difference between Elastic and Inelastic Collision

Below table describes the difference between elastic and inelastic collision. Which will help the students to undertsand the key differences in a better way.