# Why is momentum conserved in elastic and inelastic collisions?

• Sandeep T S
In summary, momentum is conserved in both elastic and inelastic collisions due to the absence of external forces. The equation for calculating momentum is p = m x v, and this concept is closely related to Newton's Third Law of Motion. Momentum cannot be lost in a collision, as the total momentum of the system must remain constant.
Sandeep T S
Why momentum conserved in elastic collision and inelastic collision? Please attach mathematical proof too

Consider Newton's 3rd law.

robphy and PeroK
Doc Al said:
Consider Newton's 3rd law.
P^2/2m ,I got it

What you wrote was just the expression for the kinetic energy. The point made by Doc Al in post #2 is that from Newton's third law, you can prove that momentum is conserved.

Chestermiller

## 1. Why is momentum conserved in elastic collisions?

In elastic collisions, the total momentum of the system is conserved because there is no external force acting on the system. This means that the initial momentum of the objects before the collision is equal to the final momentum of the objects after the collision.

## 2. How is momentum conserved in inelastic collisions?

In inelastic collisions, the total momentum of the system is also conserved because there is still no external force acting on the system. However, some of the initial kinetic energy is converted into other forms of energy, such as heat or sound, resulting in a decrease in the final velocity of the objects.

## 3. What is the equation for calculating momentum?

The equation for momentum is: p = m x v, where p is momentum, m is mass, and v is velocity. This equation applies to both elastic and inelastic collisions, and can be used to calculate the momentum of individual objects or the total momentum of a system.

## 4. How does the conservation of momentum relate to Newton's Third Law of Motion?

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. In the case of collisions, this means that the force exerted by one object on another is equal and opposite to the force exerted by the second object on the first. This results in the conservation of momentum, as the total momentum of the system remains constant.

## 5. Can momentum be lost in a collision?

No, momentum cannot be lost in a collision. As stated earlier, the total momentum of a system is always conserved. This means that any change in momentum for one object must be offset by an equal and opposite change in momentum for another object, resulting in the overall conservation of momentum.

• Mechanics
Replies
8
Views
2K
• Mechanics
Replies
12
Views
823
• Mechanics
Replies
7
Views
5K
• Mechanics
Replies
25
Views
2K
• Mechanics
Replies
53
Views
2K
• Mechanics
Replies
5
Views
3K
• Mechanics
Replies
1
Views
742
• Mechanics
Replies
11
Views
3K
• Mechanics
Replies
3
Views
758
• Mechanics
Replies
1
Views
1K