What Is Linear Momentum?

Momentum is the physical quantity that is also a vector quantity. Momentum has come up from its origin word “Moment”. When we hear the word “moment”, we get a little idea about the relation between time and some kind of motion, or we can say motion that is dependent on time.

Since the word “momentum” has been derived from the word “moment”, it has a similar sense to it. Momentum is one of the physical quantities in physics where there is one object and that object possesses some motion and that too in one particular direction at a particular time. In this article, we collected short paragraphs to make you learn about linear momentum, what linear momentum formula is, and the law of conservation of linear momentum.

What Is Linear Momentum?

Before asking, what is linear momentum? You should understand what kind of physical quantity momentum is in physics? 

Momentum is the further improvised derivation of the word called “moment.” Moment means at this particular time in simple terms. But here, momentum gets its origin from the moment because in momentum, there is one object that is not at rest, or we can say that it is moving.

Now, the object that is moving will have some forces responsible or working behind it because it is in motion. That force is applied and left because it lasts only for a fixed duration. The force applied divided by the difference in time interval for an object will define its momentum.    

Linear momentum is a category of momentum that has a vector direction like other momentum but it is straight throughout the trajectory of the object. Linear momentum is the physical quantity that depicts the momentum possessed by the object that is in some sort of motion due to attracting or repelling force acting on it.

The net momentum may be in any direction. It isn’t necessary to be either 30 degrees, 45 degrees, or 90 degrees. But, we can’t solve problems if we have to deal with multiple changing angles. Hence, we choose the concept of linear momentum along with angular momentum.

Linear momentum is the component of net momentum if we take the sinθ component of the net momentum because the direction is always perpendicular to the actual net momentum.  

Net Momentum = Linear Momentum + Angular(Orbital) Momentum

Linear Momentum Formula

Linear Momentum = Mass Of The Object X Velocity Of The Object

p = m × v

Solved Example 1: Calculate the linear momentum of a jumping ball whose mass when measured on the weighing machine came to be 20 kilograms and it is observed moving with a velocity of 30 m/s?

Solution. We will check the given parameters that are provided in the problem statement.

Mass, m = 20 kg.

Velocity, v = 30 m/s

We know that the formula of linear momentum, 

Linear momentum = Mass of the jumping ball × Velocity of the jumping ball

P = m × v => 20 kg × 30m/s => 600kgm/s.

Law Of Conservation Of Linear Momentum

The conservation of momentum principle says that two colliding objects in an isolated system have the same cumulative momentum before and after the collision. That is, momentum is not lost but transmitted between the two objects when they collide. 

Momentum is always reserved in a completely isolated system even if it collides. The momentum from the object is transferred into your surface at the point of collision when the object is struck at a wall, for example.

Consider an example of a cricket ball being thrown high up in the skies through the air to understand the working of linear momentum better. When you catch the cricket ball coming from a great height, you feel the ball’s momentum hit you. When you catch the ball, it pushes your hand back towards you. 

The momentum of the cricket ball gets transferred from the ball itself to the hands of the catcher. Because of this, you can see fielders drag back their arms a bit while catching a cricket ball so that the enormous momentum of the ball can dissolve without walloping them.

This is the perfect situation to understand the law of conservation of linear momentum because the linear momentum has to be conserved in every situation, it can be an elastic collision or inelastic collision.

Conclusion

Linear momentum also comes under the hierarchy concepts of momentum. It is a vector quantity that deals only with the measurement of the motion of any object, Linear momentum is described as the product of the mass of an object, m, and its velocity of the object, v. The dimensional formula of Linear Momentum is represented by [M1L1T-1]. The linear momentum formula has a definite role in determining the 2nd law of motion. Other than linear momentum, there is another type of momentum, and that is angular momentum. An object that spins has angular momentum, while one that moves at a constant speed has linear momentum.