Difference between Impulse and Momentum

In summary, impulse and momentum are two related concepts that describe the motion of objects. Impulse is the change in momentum of an object when a force acts on it for a certain amount of time, while momentum is a property of an object that is affected by impulse. The equations for impulse and momentum are similar to those for work and kinetic energy, but they also take into account potential energy in the case of work.
  • #1
Jadaav
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What's the difference between impulse and momentum ?

When do we use impulse or when do we say a body has impulse ?
 
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  • #2
Hello.

If a body experiences an impulse, its momentum changes. So if a force acts on an object in a short amount of time, that object will experience an impulse, and subsequently its momentum will change.
 
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  • #3
momentum is a property of moving objects...mass x velocity.
To change momentum requires a force acting for a length of time.
The quantity Force x time is called impulse and it equals the change in momentum.
So I would say impulse is used to link force with momentum.
 
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  • #4
F = ma, where a = Δv/Δt. Therefore FΔt = mΔv.

The left hand side is the impulse and the right hand side is the momentum. Both are vector quantities.
 
  • #5
technician and mark.watson both are on the right track, but I would say technician is assuming a constant force, while mark.watson is giving an infinitesimal form of the actual definition:

The definition of impulse I is
[tex]\vec{I}=\int \vec{F} \ dt [/tex] Impulse is a time integral of force.
Momentum, on the other hand, is a property of an object. If an impulse I is imparted on an object, it will change that object's momentum by [itex]\vec{I}[/itex]. To be more explicit, if the object initially has momentum [itex]\vec{p}[/itex], and then an impulse [itex]\vec{I}[/itex] acts on that object, its final momentum will be [itex]\vec{p}+\vec{I}[/itex]. So an impulse is basically momentum transferred.
 
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  • #6
Impulse is to momentum as work is to kinetic energy.

Work-energy theorem: ΔK = W (the change in an object's kinetic energy equals the work done on it)

Impulse-momentum theorem: Δp = I (the change in an object's momentum equals the impulse acting on it)
 
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  • #7
jtbell said:
Impulse is to momentum as work is to kinetic energy.

Work-energy theorem: ΔK = W (the change in an object's kinetic energy equals the work done on it)

Impulse-momentum theorem: Δp = I (the change in an object's momentum equals the impulse acting on it)

Well, work can go into potential energy too, e.g. stretching a spring.
 
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  • #8
Thanks a lot guys :)
 

What is the difference between impulse and momentum?

Impulse and momentum are both physical quantities that describe the motion of an object. However, they have different definitions and units. Impulse is the product of force and time, while momentum is the product of mass and velocity.

How are impulse and momentum related?

Impulse and momentum are closely related, as impulse is defined as the change in momentum of an object. In other words, impulse is the force applied to an object over a certain amount of time, resulting in a change in the object's momentum.

Which one is more important: impulse or momentum?

It depends on the context. In situations where time is a critical factor, impulse may be more important as it determines the change in momentum. However, in cases where the mass and velocity of an object are significant, momentum may be more important.

Can impulse and momentum be conserved?

Yes, both impulse and momentum can be conserved in a closed system where there is no external force acting on the system. This is known as the law of conservation of momentum.

How are impulse and momentum used in real-world applications?

Impulse and momentum are important concepts in physics and are used in various real-world applications such as rocket propulsion, car safety systems, and sports. They are also essential in understanding collisions and the transfer of energy in different systems.

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