## Definition of momentum in physics

**Definition of momentum in physics: **The product of the mass and velocity of an object is called **momentum.**

We already know that if there is a very large object, it is very difficult to move it. For example, if a truck is standing on the side of the road, it needs a lot of strength to move, because it is heavy.

A small bullet fired from a gun can also strike. It is also difficult to stop him. Its size is nothing compared to the truck. But his speed is very fast.

It is understood from these two things that both these things have something which is common in both – that is momentum.

**Definition of Momentum**

Linear Momentum of an object is equal to the product of mass and velocity of the object, Momentum is a vector amount and the direction of momentum and direction of velocity are the same. It is denoted by ‘P’.

Emotion depends on two things-

1) Mass (m ‘)

2) velocity (v)

## Momentum Formula

*P = mv*

*Linear momentum = mass × velocity*

## Law of conservation of momentum

If two bodies collide in an isolated system, the total momentum of that arrangement will be conserved before and after the collision.

If both bodies have velocity v1 and v1 before collision and v2 and v2 after collision, then

mv1 + MV1 = mv2 + MV2

Where m and M are the weight of both bodies. Because momentum is a vector quantity, it is preserved in both magnitude and direction.

Suppose a football player is running east at a speed of 50kmph and another player is running from 60kmph to the west and if both collide, then they will go together from 10kmph to the west. In this way, momentum will be preserved.

It is very important that the system remains separate. If there is an external force, the center of mass will not move at a speed and momentum will not be preserved.

## Proof of the law of conservation of momentum

If the external force acting on an object or body is zero, then the momentum of the body remains constant or is protected Conservative, it is called **the Law of Conservative of momentum.**

F = dp / dt

If F = 0, then dp / dt = hence dp = 0⇔⇒ p = Constant

From Newton’s Third Law of Motion, we know that every action has the same magnitude but the opposite reaction. (every action has an equal and opposite reaction)

The force ‘F’ in the action is the product of the weight ‘m’ of that object and its acceleration ‘a’.

So if object 1 exerts ‘ma’ force, then object 2 exerts ‘- ma’ force. Yanni –

m1a1 = – m2a2 —- (1)

Now the velocity of a (velocity) changes over time –

a = ∆v / t —- (2)

As long as object 1 exerts force, as long as object 2 exerts force. That is, object 1 and object 2 will be in contact with each other for the same time. Therefore, we can remove t from both sides in the equation.

By doing this, we will get –

Which is the principle of momentum conservation.

Therefore, if the external force charged on an object is zero, then its cue remains constant.

## Example of Conservation of momentum

- A gun and bullet is a system of particles, when firing from a gun, there is a backward shock and the bullet goes forward, but the gun has a lower shock than the bullet because the mass of the gun is less than the mass of the bullet. Is greater so that the retraction velocity of the gun is much less than the velocity of the bullet.
- Suppose a football player is running at a speed of 50kmph to the east and another player is running at 80kmph to the west and if both collide, the two will go together from 30kmph to the west. In this way, momentum will be preserved.
- If an object of two equal mass collides with equal velocity in the opposite direction, both objects will stop due to the equal moment Momentum of both objects, due to which the moment will be fixed.
- The upward movement of the rocket is based on the law of momentum conservation. The gas escapes rapidly from the hole behind the rocket, causing the rocket to move forward.

It is known from all the examples that in every circumstance, the celiac is preserved.