# What is Momentum transfer: Definition and 42 Discussions

In particle physics, wave mechanics and optics, momentum transfer is the amount of momentum that one particle gives to another particle.
In the simplest example of scattering of two colliding particles with initial momenta

p

i
1

,

p

i
2

{\displaystyle {\vec {p}}_{i1},{\vec {p}}_{i2}}
, resulting in final momenta

p

f
1

,

p

f
2

{\displaystyle {\vec {p}}_{f1},{\vec {p}}_{f2}}
, the momentum transfer is given by

q

=

p

i
1

p

f
1

=

p

f
2

p

i
2

{\displaystyle {\vec {q}}={\vec {p}}_{i1}-{\vec {p}}_{f1}={\vec {p}}_{f2}-{\vec {p}}_{i2}}
where the last identity expresses momentum conservation. Momentum transfer is an important quantity because

Δ
x
=

/

|

q

|

{\displaystyle \Delta x=\hbar /|q|}
is a better measure for the typical distance resolution of the reaction than the momenta themselves.

View More On Wikipedia.org

8. ### Momentum transfer from linear to angular motion

I am trying to create a momentum trap to calculate the velocity of a projectile when it hits the trap. It essentially consists of a plate if known mass at the bottom of a pendulum of known radius. When the projectile hits the plate, the degrees that the pendulum rotates are recorded. I believe...
9. ### A Momentum transfer perpendicular to velocity of proton?

An assumption in deducing the Bethe equation is that the momentum transfer is perpendicular to the direction of the particle. ALSO In Allison & Cobb (1980), just after eq. 28, they state that the first two terms of the Photoabsorption Ionization model arise from the magnetic vector potential...
10. ### Transfer of Momentum during a collision

For an inelastic impact situation where two bodies traveling in opposite directions (vehicles say) collide and coalesce (perfectly inelastic collision) , one can derive the following expression for equal and opposite transfer of momentum. On the basis that if impact forces are equal and...
11. ### I Why doesn't momentum transfer on mirrors reveal which path?

Hi. In a Mach-Zehnder interferometer, there are mirrors in both paths. When a photon gets reflected on a mirror, it transfers momentum. Also, mirrors are classical objects that are usually not assumed to exist in superposition states. Shouldn't it (at least in principle) be possible to measure...
12. ### Direction of momentum transfer?

Does the momentum always get transferred from lower velocity to higher velocity(may be along a negative velocity gradient.) Consider the collision between 2 bodies M1 and M2,(M1<M2) but both having the same momentum.So M1 will have a higher velocity than M2(V1>V2). Now if the velocities V1 and...
13. ### Momentum Transfer: Elastic Collision vs Inelastic Collision

In elastic collision momentum and kinetic energy are conserved. Where as in inelastic collision K.E. and P are not conserved since K.E. lost during deformation in target object is consistent with momentum conservation. The question here is in context of working out with a 70kg heavy bag (m2 )...
14. ### A Momentum transfer and energy scale

Hi, I am recently working on a project involving simulations and I'm pretty confused about the parameter energy scale Q (contained in TruthEvent pdfInfo). I tried to figure out what that parameter means and from some sources online I think Q is the absolute value of momentum transfer q...
15. ### Momentum Transfer in Scattering

Homework Statement This is just a simple proof of substitution, but after one day struggle, I still can't get where that minus sign appear. Homework Equations Here is the equation: $$(p_1 - p_3)^2=-(\mathbf p_1 - \mathbf p_3)^2$$ where ##p_1=(E/c,\mathbf p_1)## and ##p_3=(E/c, \mathbf p_3)##...
16. ### Light Momentum Transfer between point charges

Hi, I am trying to understand how light momentum transfers between point charges. I have a few questions if you could help me find some answers or direct me to some sources. Situation #1 Electron/Wire - There is an electron at rest light years away from a wire that has AC flowing thru it...
17. ### Light reflecting off sphere -- Momentum transfer

Homework Statement Suppose light of momentum -P\hat{\textbf{k}} is shone on a sphere of radius R. What is the momentum transferred onto the sphere? Homework Equations The Attempt at a Solution I think the transferred momentum upon reflection is given by (-2P\hat{\textbf{k}} \cdot...
18. ### Conservation of energy and momentum transfer

Let's say a tennis ball with velocity with only an horizontal component hits a vertical wall at rest. After collision, conservation of momentum tells that : m_{wall}v_{wall} = 2m_{ball}v_{ball} Thus, the wall has now a (tiny) velocity and kinetic energy : v_{wall} =...
19. ### Regarding momentum transfer, couple questions.

Hello, I've been learning calculus and physics for the last year. Let's say i have 2 point masses mass one (m1) and mass two (m2). Their respective velocity vectors are constrained to one spatial dimension, with the directional component of their velocity vectors being determined by their...
20. ### Exploring Asymmetry Momentum Transfer for Space Propulsion

Momentum Drive =============== Just playing with some ideas on rocket propulsion in space based on asymmetry momentum transfer. Any reason why this is not workable? :-p 1. Let m1 = 100 kg robot arm at one end of a cylinder; m2 = 100 kg robot arm at opposite one end of the cylinder; m3 = 10...
21. ### What formula can I use to calculate momentum transfer?

< Moderator Note -- moved from Academic Guidance to Homework Help > Hey, I'm new here, I decided to register because one of the threads has helped me in the past and I'm hoping for some answers; to get into it, I'm doing research on the physics of being hit by a car/truck, and I've got most the...
22. ### Momentum transfer when object falls into black hole

Let's imagine a stationary black hole and a fast moving object falling into BH. Let the momentum of the falling object be enough to give an observable bump to BH, pushing it into motion. Since the object does fall into BH, by momentum preservation BH should start moving. But I don't see how...
23. ### Momentum transfer: Trolley colliding with spring

Homework Statement A trolley travels with constant velocity to the right on a horizontal ground and collides with a light helical spring attached to a wall fixed to the ground (earth) as shown. At the instant that the trolley comes momentarily to rest during collision, what has happened to...
24. ### Speed of freight car (momentum transfer)

Homework Statement This is problem 3.9 from Kleppner & Kolenkow's Intro to Mech. A freight car of mass M contains a mass of sand of mass m. At t = 0, a force is applied in the direction of motion, and simultaneously sand is let out of the bottom of the car at a rate dm/dt. Assuming the...
25. ### High-energy physics: momentum transfer

Homework Statement I have an electron of 20 GeV and negligible mass that collides with a stationary proton (mc^2 = 9.38 GeV) and deflects at an angle of 5°. I'm asked to find the square of the four-momentum transfer, q2Homework Equations q = P - P', where P/P' is a 4-momentum vector <px, py...
26. ### The classic momentum transfer between balls question

Homework Statement A 5.0-kg object has a velocity of 6.0 m/s, east when it explodes into two 2.5-kg objects. After the explosion one of the objects has a velocity of 4.0 m/s at an angle of 50° north of east. What is the magnitude and direction of the velocity of the other object after...
27. ### Question about momentum transfer

Hi. I'm trying to figure out how transfer of momentum works so that I can simulate it reasonably accurately and understand it on an intuitive level. My intuition goes like this: Momentum must be conserved. Therefore, if for example I had a 1 meter long Newton's Cradle with numerous polished...
28. ### Elastic collision momentum transfer

Consider a collision between a large and small body (golf club/hockey stick/baseball bat and a ball for example). How is it possible to calculate how much the momentum of parts of the body removed from the collision contact point have an effect on the momentum of the smaller body before it...

deleted
30. ### Link between momentum transfer and distance

hi folks, readingthis post: https://www.physicsforums.com/showpost.php?p=992445&postcount=11" I was wondering why this distance of interaction is smaller at higher momentum transfers. Could anyone explaine the link between momentum transfer and distance? derivator
31. ### Momentum transfer dependent on distance?

Does the amount of momentum transferred by an EM wave to a particle differ by how far away the particle is from the EM wave emitter? The more spread out the EM wave is, the less momentum transfered? I'm not talking about a collision between a photon and a particle; I'm talking about the...
32. ### Momentum transfer in a first class lever

We have a seesaw arrangement, a mass m3 supports the fulcrum, we have mass m2 on one end, and a mass m1 fall on the other end with velocity v. Considering the distance between the fulcrum and m1 is d and that of m2 is r, what will be the momentum distribution?
33. ### Momentum Transfer: Does Light Mass Gain Momentum?

http://img141.imageshack.us/img141/476/explainimageiy6.jpg The blue ball is a gear actually, with 2 racks on both its side which are attached to 2 masses each (M1 = M2). If momentum is made to gain in the arrangement from the side M2...it will also impart momentum to M1. Suppose all...
34. ### High momentum transfer, short distances

Hi there! I have some problems understanding the connection between high momentum transfer and short distance behavior. I know that the QCD coupling goes to zero as the momentum transfer Q^2 approaches infinity. Most introductory HEP textbooks say that this means that the quarks in the nucleons...
35. ### Exploring Momentum Transfer in Aircraft Motion

momentum transfer? when aircraft is in motion, it has momentum. Since it has momentum, there is momentum transfer taking place between the aircraft and the air particles. During this momentum transfer what exactly is happening between the wings and fluid particles that are present right...
36. ### Photon Momentum Transfer & Energy Conservation

The photon comes in with momentum p and leaves with the same momentum in the opposite direction. The sail picks up a momentum of 2p in the original photon's direction. Energy conservation states that: h\nu_1=h\nu_2+\frac{(2p)^2^}{2m}=p_{1}c=p_{2}c+\frac{(2p)^2^}{2m} Isn't |p1|=|p2| thus...
37. ### Uncovering the Mystery of Wave Momentum Transfer

Apparently what I thought I understood about waves is wrong: there seems to be a net momentum transfer with mechanical waves, as well as photons (it seems they're perfectly analogous). I hope some of the experts on the board can help to clarify this issue; perhaps it’s less surprising to...
38. ### Exploring Momentum Transfer: F(q)^2 Factor & Spherical Symmetry

I have a form factor that only depends on the momentum transfer q, this is symbolised by writing the form factor as F(B]q[/B]^2). if i have a spherical symmetric distribution of charge, f only depends on the radius; r = | q| Then integration over all solid angels yields...
39. ### Question about momentum transfer from fluids to discrete particles

Hi, I am having trouble find information on the following topic, I think mostly in part because I don't know the correct terminology. Basically, I have a number of particles that are falling at their terminal velocities within a gaseous fluid, and turbulent velocity fluctuations in the fluid...
40. ### Maximizing Momentum Transfer in Space Ships: A Guide for Optimal Performance

Could something like this be used for a momentum Tranfer in Space Ships?:bugeye: If so, Then how could we improve upon it? If not then kindly disregard this post. Maximize for better reading.
41. ### What is momentum transfer cross section ?

What is "momentum transfer cross section" ? Hi all, I'm reading a book on electron-molecule interactions and I'm puzzled by a quantity (well, by the difference in definition of two quantities). The book is, for your information, "fundamental electron interactions with plasma processing gases"...
42. ### Is Snooker's Momentum Transfer Real?

In snooker, I've noticed many times that it you hit some ball in right place the white ball will stop at the point of contact but the ball that was hit starts moving. Is this true that the white ball tranfers all of its momentum to the other ball and since there is no more momentum left it stops?