Interaction between two or more bodies that results in physical contact and an exchange of momentum between the bodies involved.

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Where did the energy of the charge go?

Suppose there is a positron and an electron, and they both collide, and we get $E=2mc^2$ of energy from the collision. Now, the charge also got vanished. Now suppose, I create neutrinos from the ...
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2answers
105 views

Properties of an object whose collision with Earth would completely disintegrate Earth

This picture got me thinking, whether such collision would be possible, and would it really look like that from the moon. What would be the properties (mass, size, velocity etc.) of an object, whose ...
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3answers
480 views

Collision of two balls [duplicate]

Two balls, with masses $m_1$ and $m_2$ are falling from the heigh $h$. All the collisions are perfectly elastic. Do not consider the size of the balls. $m_1 < m_2$ and lighter ball is on the top. ...
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1answer
59 views

Something about collision [closed]

A sphere P of mass m, travelling with speed $u$, makes a head-on collision with a stationary sphere Q also of mass m. After the collision, the velocities of P and Q are $v_1$ and $v_2$ ...
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3k views

Two objects exert forces on each other, will the reactions affect them?

Two objects go in against each other, and then they collide, will object 1, exerting force 1, necessarily get on it a reaction equal in magnitude and opposite in direction? EDIT:- In my book it only ...
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69 views

Does elementary particle emit photon?

Charged particles are accelerated by the magnetic field in a particle collider before allowed to smash together at specific location where the detectors are housed. My question is do the ...
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106 views

Two balls travelling at different speeds collide in two referentials

In a referential R1, one ball B1 travels at 100 m/s and hits and another identitcal ball B2 that travels at 50 m/s in the same direction. Assuming the material in which the balls are made is such that ...
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1answer
71 views

Linear Momentum Based Problem [closed]

A ball moving along a straight line collides elastically with another stationary ball of the same mass. At the moment of collision the angle between the straight line passing through the centres of ...
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174 views

Conservation of Momentum: Perfectly Elastic Collision, Example Problem

I am a middle school science teacher. I'm a little rusty on my physics knowledge, and I came across a question that I feel like I should be able to solve, but it also feels like there is a piece of ...
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139 views

Question on the negativity of the coefficient of restitution

I was trying to solve a Mechanics question on Momentum. Here is the question : Two small smooth spheres A and B have equal radii and have masses m and km respectively. They are moving in a ...
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497 views

A spring with two masses in an inelastic collision

An ideal spring is attached to a wall, and the other end is attached to a mass $m$. The spring is initially compressed a distance $x$. After it is released, the mass collides with another mass $2m$ ...
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343 views

Calculating velocity change after impact?

Let's say there is no gravity here and objects won't crush. We have 2 rocks with $m=10\text{ kg}$. First rock has velocity $v_1=0\text{ m/s}$ and second $v_2=10\text{ m/s}$ (flying in leftward ...
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45 views

Capturing Energy from a Positron-Electron Collision

According to the book Physics of the Impossible, the catastrophic collision between a electron and a positron yields an output of 1.02 MeV. Assuming you have an isotope like $^{22}\text{Na}$, which is ...
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1answer
62 views

absorption length of thermal neutrons in a medium

My book states that $$N(x)=N_0\cdot e^{n\cdot \sigma \cdot x}$$ for $n$ absorbing particles per volume element with a cross section $\sigma$. Can somebody explain where this comes from?
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125 views

How do you make a collision more elastic?

Currently, as described in this question, collisions cannot be elastic. However, is there a way to make a collision more elastic? Background: We're working on a project right now involving high ...
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1answer
86 views

Bullet: Piercing vs. Deflection

I am trying to create a simulation where a projectile (imagine a bullet) is fired at a surface of some kind. When it collides with the surface, I need to figure out what happens between the bullet and ...
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2answers
787 views

Simple conservation of momentum and frame of reference problem

I'm making a very simple physics engine based on momentum, and I'm solving what response to use for a collision from each involved object's frame of reference. However, something about how I'm ...
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14k views

Calculating force of impact

Since $\text{force = mass}\times\text{acceleration}$, is it right to say that an object traveling at a high constant velocity (zero acceleration), exerts zero force upon impact with a stationary ...
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1k views

Elastic Collision And Momentum

The question I am working on is, "Two blocks are free to slide along the friction-less wooden track shown below. The block of mass $m_1 = 4.98~kg$ is released from the position shown, at height $h = ...
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1answer
124 views

A Decrease In Momentum?

The specifics of a question I am working on are, "After a 0.280-kg rubber ball is dropped from a height of 1.80 m, it bounces off a concrete floor and rebounds to a height of 1.45 m." Why doesn't the ...
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2answers
779 views

How to calculate the coefficient of restitution for 2 bodies?

I have 2 rigid bodies (from different materials) in a collision. As you know I should have the coefficient of restitution value to get the velocities after collision. What is the information/values ...
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1answer
636 views

How are these balls reflected after they hit each other? [duplicate]

Possible Duplicate: Physics of simple collisions I have 2 photos of the balls, one before the collision and one after the collision. They do a elastic collision. I want to know how is the ...
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42 views

Do inelastic or elastic collisions have any effect on a large bodies movement (like the Earth)

Recently read a question regarding the temperature of the CMB & one of the comments got me thinking... From what I understand, collisions between subatomic particles and objects out in ...
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1answer
31 views

Definition of a symbol $s_{NN}$ appearing in particle physics

What is the meaning of $s_{NN}$ in particle physics? See e.g. here http://www4.rcf.bnl.gov/brahms/WWW/thesis/karabowicz_phd_thesis.pdf page 18 in the pdf. What is its relation to energy? I ...
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1answer
48 views

How to calculate the deceleration of two trains moving with the same velocity? [closed]

Two trains travelling on the same track are approaching each other with equal speeds of 40m/s. The drivers of the train begin to decelerate simultaneously when they are just 2km apart. If the ...
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3answers
72 views

Why doesn't an object that collides with one that is at rest just do a 180?

Newton's third law says "for every action, there's an equal and opposite reaction." So why is it, say, that when a pool/billiards ball hits the wall of the table, the ball doesn't just turn around?
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75 views

Domain of different types of collision?

Can anyone tell me why elastic collision occur between atomic particles? inelastic collision occur between ordinary objects? perfectly inelastic collision occur during shooting? ...
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1answer
67 views

Why does accounting for direction give the wrong result for a bouncing ball?

This a conservation of momentum problem, gathered from an old textbook. I thought it would be simple, but I seem to be goofing up somewhere in my basic conceptual understanding. PROBLEM: A 1.0 kg ...
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1answer
138 views

Having problem in understanding the coefficient of restitution

Newton discovered that the relative velocity of separation of the two bodies after the collision is always proportional to relative velocity of approach before collision. The proportionality ...
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1answer
139 views

Help with equations for deflecting an asteroid

This is a homework assignment, but not the physics part. I have to write a python script to simulate the size of a warhead required to deflect an asteroid (parameters inputted by user) that is on a ...
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2answers
112 views

Ballistic Pendulum Demo Problem

I have a question about the following problem: I got the solution $v=\frac{M+m}{m} \sqrt{2gh}$. But my real question is in the following picture: In the above slide, how can you derive ...
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1answer
38 views

Collision of a heavy charged particle with an electron at rest - Deduction

When I was studying Nuclear Physics I saw this formula about interaction of radiation with matter. The book mentioned that when considering a elastic collision of a heavy charged particle of mass $M$ ...
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1answer
230 views

Bullet hits block. Show that linear momentum is not conserved [closed]

"..." First, we will familiarize us with a collision between a homogeneous beam of length, $L$, mass $M$ attached with a frictionless hinge in point $O$ at one of the endpoints of the beam. The ...
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1answer
138 views

Angular momentum of two rotating spheres

I am trying to calculate an instantaneous merger of two rotating spheres into one. Two spheres each rotating around their own axis of rotation (which are generally not aligned) and moving relative to ...
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1answer
968 views

Loss of kinetic energy in inelastic collision [duplicate]

I know that momentum and energy are always conserved in collisions, but if we have a perfectly inelastic collision in which an object sticks to another object $m_1 v_1 + m_2 v_2 = (m_1+m_2)v_{12}$, ...
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1answer
142 views

Relative Velocities and Conservation of Kinetic Energy

An object of mass m moves with velocity $v$ towards a stationary object of same mass. Impact is an elastic collision. $v_1$ is the velocity after impact of the mass originally moving $v_2$ is the ...
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68 views

Distribution of Kinetic energy after an Impact

How does the huge amount of kinetic energy of some fast object like a meteor or rocket etc. gets distributed into various kinds of energy like kinetic, sound, light etc after making an impact with ...
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1answer
598 views

How can I calculate the time until collision?

I'm programming a 1 dimensional physics simulator in python. How do I calculate the amount of time until two particle points that are traveling towards eachother collide? I am using the equation: ...
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1answer
451 views

effect of object mass in coeficient of restitution

I know the coefficient of restitution depends on the velocity before and after the impact of a bouncing ball. How does the mass affect it. Can't figure it out. v ...
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1answer
451 views

Do particles ever touch each other during a collision? [duplicate]

Do particles ever touch each other during a collision? My understanding is that they can get really close to each other but never actually touch, is that true? Another thing I've read about is, the ...
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1answer
200 views

Antimatter collision - Energy Released

I think it's about time for me to ask this question, as I've been contemplating this for a while. $$E = mc^2.$$ This is Einstein's most famous equation. But what does it mean? On my own, I had to ...
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1answer
83 views

Direct collision on smooth surface

Hello I have a problem on my hands an I cannot figure out the answer. Two spheres of equal mass on on a smooth surface. sphere 1 is moving at $2v \ m/s$. Sphere 2 is stationary and 1m from a ...
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1answer
109 views

Storing kinetic energy in bonds

Let's assume a setup with a static linear molecule with three identical atoms connected by bonds and a single atom, identical to the other three, being shot at the molecule. Let's also assume that ...
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1answer
501 views

Newton's Third Law and Constant Velocity

How can an object that's not accelerating cause another stationary object to move in a collision? This website: http://www.physicsclassroom.com/Class/momentum/U4l2a.cfm, says that a "rightward moving" ...
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1answer
110 views

Question about Cars: Momentum

Car B rests at the bottom of a frictionless inclined plane. In order to travel a height of 0.6m and maintain a speed of 2 m/s at the end of the track it needs to start with 4 m/s. a) If ...
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1answer
276 views

Calculate force of impact on running dog

I'm going to hold a dog protection tournament. I'd like to give the audience information about the force of the impact of the running dog when it hit(attacks) the decoy on a huge screen. I'm a ...
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1answer
699 views

Bouncing ball simulation computer science

In my Computer science class I was given a problem where I have to simulate a bouncing ball using "real physics". I have been trying to find a equation that will simulate the height of the bounce ...
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1answer
84 views

Do particles in the solar core travel at the same speed as they would in vacuum?

I just read the Wikipedia article on the Sun. The section on Solar Core states It has a density of up to 150 g/cm3[47][48] (about 150 times the density of water) Do the particles (atomic, and ...
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1answer
217 views

Newton's second law?

$F=ma$. A car strikes a wall at 60 mph. Its acceleration is zero at the time. The force of the car against the wall or vice versa is? To look at the car the force is not zero. Please explain.
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97 views

Minimum $E$ of $p\bar{p}$-collision for $q\bar{q}$ pair with mass $m_q$

I am currently working out the energy required to create a particle anti-particle pair from a collision of a proton travelling along the x-direction with an anti-proton which is at rest. The particle ...