Impulse vs Momentum: Comparative Analysis and Detailed Facts

Impulse vs momentum is the main topic that often is misunderstood often while talking about systems in motion. Momentum is the quantity of mass in motion and impulse is the quantity of force triggering motion.

When the body is triggered to work under motion it is to be noted that so many different factors come into an act that is responsible for the movement. When the body is at rest the momentum is the mass that is there but when it is in motion the momentum changes.

The change in momentum is often regarded as an impulse. When a particular system is under motion the force is the main reason for its movement and this force will be changing according to the time that will change for each time interval.

Momentum is somewhere related to the Newton’s Second Law which is the motion will change according to the kind of force applied and the mass of the system along with velocity. It is evident from the fact when a body has mass it will have velocity when in motion.

When in motion it will gain some momentum to move further into the motion. Likewise when there is a change in momentum then the concept of impulse will peak through. Quantities like impulse and momentum are vectors both having magnitude and direction.

When we generally discuss the impulse vs momentum we usually come into the confusion of which is the factor that will contribute mainly to the motion of a body. We know that impulse and momentum will both provide a better phase for the motion of a body.

Can Momentum and Impulse be the same?

No, scientifically impulse and momentum cannot be the same. In fact, the change in momentum is basically named impulse. Impulse is simply the increase or decrease of momentum in a body that is under constant motion.

In an inertial frame reference, the frame of reference is basically the non-accelerated one. When the frame of reference does not undergo any motion nor be accelerated to any different speed then it is known as an inertial frame of reference.

When in an inertial frame of reference the impulse is zero because there is no momentum present and the force. Velocity, acceleration all these quantities will be at rest or zero. When the net force is zero in a non-inertial frame of reference then the impulse is said to be zero.

Hence it is a known fact from the studies that the impulse and momentum cannot be the same because the impulse is the measure of momentum which deals with the mass, velocity, and applied force of the system whether under motion or not.

Formula for Momentum and Impulse

Momentum is basically the product of mass and the velocity with which the body moves in motion. So when the speed changes the momentum needs to be increased in order to move further in motion. This change in momentum is known as an impulse.

Rather the impulse can be also told as the force applied on a body multiplied by the elapsed time over a particular period. For instance, when a bowler bowls the ball it will strike the bat at a particular speed.

The force with which the ball hits the bat at that time is determined in terms of an impulse. Impulse is simply the force that is multiplied by time which changes from second to second. This has a different formula for momentum and impulse.

Even in terms of formula momentum and impulse cannot be the same. The formula for momentum is the product of mass and velocity, p = m x v, whereas, the impulse is given by the change in momentum which is the product of applied force and elapsed time interval, ΔP=FΔV.

What are the similarities between Momentum and Impulse?

The main similarity between momentum and impulse is that they both are connected to Newton’s Second Law. When momentum is the product of the mass of the body and its velocity with which it moves further and impulse is the change in momentum.

Momentum basically deals with the mass and the velocity of a body, for instance when a car is at rest it will have certain momentum but when it accelerates it need more momentum to move from its equilibrium position so the change in that momentum is measured by impulse.

When we usually consider Newton’s Second Law it deals more with the change in momentum at a particular rate of time. So when an object under motion will have momentum and that will change according to the circumstances.

One main similarity is that both impulse and momentum depend on mass, force, velocity, and acceleration both have major effects and impacts on elastic and inelastic collisions. When we consider the collisions the momentum is usually conserved in elastic collisions.

In an elastic collision, the energy is not lost it is conserved but momentum is also sometimes not lost. But in an inelastic collision, the momentum is not conserved since there is a major loss in the kinetic energy. The side effect of the conservation of energy is the change in momentum.

Impulse vs change in Momentum

There is no such thing called as impulse and change in momentum because both mean the same, in fact, the change in momentum is regarded as the change in momentum.

When the momentum is changed the mass has to be increased but instantly changing the mass is tedious. To match the change in velocity the momentum has to be changed. For instance, let say a car is at rest and it has some minimal amount of momentum when it has to start the motion momentum will change.

In another instance, a bike goes at a particular speed with some amount of momentum but then the road is free to ride fast so the driver changes the gear and speeds up the vehicle, at this instant the momentum will definitely change and this change is called impulse.

When a ball is rolled from a height it will keep rolling until it faces a sudden stop and then starts rolling again there is a small change in momentum where the velocity is changed from time to time according to the circumstances.

Impulse vs Momentum Transfer

The difference between an impulse and a momentum is that momentum would change when velocity changes and the change of momentum is impulse.

Momentum transfer happens when a particle collides. For example, when in nuclear fission the particles rearrange in different forms as in they will separate into different particles. So there will be a momentum change in this case.

When any two bodies come in direct contact with each other they will collide and there will be a transfer of energy as well. So the momentum transfer is common between such particles or bodies.

Impulse is simply the change in momentum but the momentum transfer is a whole different thing altogether. The momentum can be transferred only when the bodies come in direct contact with each other.

Frequently Asked Questions

What is momentum in real life?

When the body is at rest then there is said to be zero momentum, but once the body is in motion then there is said to be momentum.

A cycle is kept at a garage for days and it gains zero momentum but has mass, and this mass needs to be moved further with the help of an external force. So when anyone tries to ride that cycle it will instantly gain momentum and will come under motion.

What law does impulse and momentum come under?

The vector quantities impulse and momentum directly come under Newton’s Second Law.

When the body is said to be in motion it will certainly have some amount of momentum in it. When the body undergoes a change in speed the momentum will change accordingly with time as well. And this change in momentum is known as an impulse.

Explain one a real life impulse and momentum example?

Certainly, games and sports will be the better examples to explain impulse and momentum in the most understandable way.

In a basketball game, the players keep passing the ball until it is forced to shoot it a time when arrived. At that time the time when one single player tries for a basket the momentum of the ball will change instantly because an extra push is given externally. The change in momentum of the ball will certainly give rise to the impulse. In this way, the process keeps repeating and we could very well understand the concept better.

4 basket
“Basket Ball” by Nazly is licensed under CC BY-NC-SA 2.0

Therefore by detailing this topic we clearly understand the terms impulse and momentum are two different aspects although having similarities.

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