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

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Collision symmetry and measuring the asymmetry in the Drell-Yan process

I saw a talk the other day about an asymmetry in the Drell-Yan process caused by CP-violation: Apparently one way this can be measured (ATLAS is doing this) is to collide protons and observe the ...
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1answer
29 views

A homework problem involving collision [closed]

A bullet of mass 25g is fired horizontally into a ballistic pendulum of mass 5.0 kg ang gets embedded in it If the centre of the pendulum rises by 10cm.Find the speed of bullet My approach: let ...
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4answers
73 views

Is there difference in force when the height increases?

Consider a man with mass 50kg. When he jumps from a 2 meter height, the total force is $F=ma$ ie (mass * gravity), but nothing happens to him. When he jumps from a 50 meter height, the total force ...
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1answer
19 views

Doubt about time interval between two consecutive rebound of a ball falling freely [closed]

While studying about rebounding of a ball falling freely from a height $H$, which rebounds for a height of $h$, the time interval between 1st rebound and 2nd rebound is $T = 2 e^2\sqrt ...
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2answers
91 views

Why does a continuous water stream form ripples when colliding with a surface?

I was in the shower one day washing my hair, and noticed that the water falling off my hair formed perfect streams that ceased to break into droplets for quiet some distance (probably about 5-6 cm). ...
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4answers
47 views

Car Crash Scenario [closed]

Two vehicles travelling at 80mph in the same direction. Vehicles are directly behind each other. 12 meter distance between them. Front door of car in front rips of and hits the front window of the ...
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2answers
141 views

Why don't electrons collide among themselves

The Heisenberg principle states that we cannot ascertain simultaneously the position or momentum of any small particle. However slight, is there a chance that 2 or more electrons from the same or ...
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2answers
21 views

Collision of Inelastic ball above the ground

An inelastic ball of mass $m$ is dropped from a height $h$ above the ground and at the same time a second ball of mass $m_1$ projected vertically upwards to meet the former. Show that in order that ...
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1answer
68 views

Problem conserving 4-momentum at CoM frame in an inelastic collision [closed]

I am confused about the case where mass is not conserved in a collision (not due to relativistic factors). The center of momentum (CoM) frame is not the same before and after the collision. Let's ...
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5answers
767 views

What happens when two photons collide with one another, head on, dead center? [duplicate]

If two photons were to collide directly, head on, and are of the same energy, what happens? Are new particles created, is energy released? Or do they just pass through one another?
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1answer
42 views

How is the final velocity in 2 body collision distributed between the 2 bodies?

Suppose 2 sphere of mass 1Kg move with velocity 5m/s and 10m/s in same direction. Let us call the ball moving with 5m/s blue and other one red with blue ahead of red from origin. Initial KE of Blue = ...
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2answers
89 views

Intro Mechanics: Finding ball speeds after collision

So I'm reading about conservation of energy, momentum, balls colliding etc. and unsurprisingly there are hundreds of questions in my textbook where essentially they give me some of the variables (m1, ...
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3answers
92 views

Trajectory of rolling billiard ball after collision with another billiard ball with same mass

So, according to this article http://www.real-world-physics-problems.com/physics-of-billiards.html , the trajectory of white (cue) ball is always perpendicular to the line connecting center of ball ...
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3answers
61 views

Force to deflect ball colliding with wall

Suppose I have a ball with a certain coefficient of restitution. The wall can be considered indeformable and with infinite mass. Everything's in 3 dimensions, and the ball can hit the wall at any ...
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1answer
32 views

Applying impulse to velocity

I'm writing physics engine and so far got some good results but stuck on 1 task i would like to ask. Got some mistake in my formula. Here is a question:Imagine 1 square colliding into another one. ...
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1answer
41 views

What does the second solution in an elastic collision represent?

A ball of mass 2 collides with a stationary ball of mass 1 elastically! In finding the velocities i end up with two solutions and am not sure how to understand the second solution Simplified ...
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2answers
44 views

What conditions would allow planetary-sized objects to collide and remain intact?

I am modeling some off-the-wall scenarios to try out with a game engine. One idea is trying to make a planet where some weird catastrophic incident has creates a funny shaped planet. I'm hoping to ...
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0answers
27 views

Star collision observation

What would these scenarios look like in real world? I mean, what the result would be?: 2 stars (not necessarily same mass) will collide "side by side", like in, they originally were traveling ...
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1answer
58 views

Changing linear to angular velocity

Suppose a 1m rod with a hook is travelling at $v$ m/s, and the hook is caught on a hanging line. The rod will change its translational motion into rotation around the hook. Since it is not an ...
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1answer
27 views

coulomb collision

I was reading an article by N. Bohr and came upon the following problem (the following wording is actually taken from a book by Thompson - Conduction of Electricity Through Gases): Let $M_1, M_2$ ...
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1answer
26 views

Comparison of the effects of collisions from an NFL Nose Tackle and a Car with roughly the same momenta

If you get hit an NFL Defensive Tackle who runs at roughly 17mph (7.6m/s) it'd hurt a lot, but if you got hit by a normal car at 1.3mph (about 0.6m/s) it hardly hurts at all, and a collision from an ...
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1answer
38 views

Particle hitting particles attached with springs [closed]

In classical mechanics if you have a particle moving in two dimensions and it hits a particle at rest although that particle is attached to a spring that is in turn attached to a third particle. ...
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2answers
48 views

Ideal energy to study higgsstrahlung at a lepton collider

Referring to this diagram: I understand that any energy excess could be taken away as kinetic energy of the final $h$ and $Z$. If you are interested in this (kind of) process should you tune the ...
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2answers
69 views

If one object, moving at a constant speed collides with another object - which is at rest - how much force has been applied?

This is one question for which an answer doesn't really make intuitive sense. In elementary school, we learn F=ma, but where's the "a" in a collision such as this? Edit: Plus, there has to be a force ...
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4answers
5k views

What would put a harddisk drive (HDD) under 350G's of force?

I always see the label and it says 350G's withstandable. What would put this over 350G's? Is it even possible to hit 350Gs of force to a hard drive?
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1answer
139 views

How to calculate impulse force on collision?

I've made a program which is supposed to simulate free fall of a ball on a ground. For collision with the ground I relied on calculating the impulse force with the answer in this Phys.SE question ...
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1answer
136 views

Newton's law of restitution

Newton's law of restitution. Could someone tell me what the easiest form of this law to use is? I usually try to use e=(v(2)-v(1))/(u(1)-u(2)). Does the law also work if I don't know the direction of ...
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1answer
63 views

Cube bouncing off a wall

An elastic cube sliding without friction along a horizontal floor hits a vertical wall with one of its faces parallel to the wall. The coefficient of friction between the wall and the cube is ...
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2answers
42 views

Collsion in 2D, find angle and final momentum

Suppose that the collision is completely inelastic. Disregard friction as the surface is smooth. Suppose that one is in the direction of $(1,0)$ and the other $(0,1)$. Is the final momentum the ...
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0answers
89 views

momentum equation to find velocity of solid particle after collision [closed]

If a particle collides with a liquid drop, particle might penetrate into drop and so the velocity of particle reduces. i.e. a sudden change in particle velocity happens right at the collision moment, ...
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0answers
29 views

Can antimatter becomes black hole? [duplicate]

I know it seems unlikely to accumulate sufficient amount of antimatter to let it collapse under its own weight to become a black hole(maybe the gravity works differently I don't know) since they will ...
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2answers
67 views

Can we create heavier particles with high energy?

It is known that an electron and a positron are created from the energy of gamma ray, is it possible to create heavier particles like proton and neutron from the energy of gamma ray? (if so what is ...
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40 views

One extra conservation equation or angle relation for a relativistic collision

Edit: It seems that the derivation for the center of momentum frame was incorrect, due to the fact that the center of momentum velocity changes after the collision. This is also true for the ...
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1answer
28 views

Collision and momentum conservation principle

Consider the following problem: A ball is dropped with an angle a between its direction and the normal of the floor and bounces up with an angle b between its direction and the normal of the floor. ...
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2answers
62 views

Cosmology: collisionless vs collisional fluids?

I try to understand the difference between collisionless and collisional fluids in cosmology. My first question is the following. In the context of FLRW cosmology, we suppose that the Universe can ...
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1answer
77 views

After a glancing collision, why do air hockey pucks spins around in circle?

For a lab testing the conservation of momentum, I had to hit an air hockey puck so that it would hit another stationary puck in a glancing collision. After the pucks collided, they travel their ...
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3answers
117 views

Why does it hurt more to fall from 10 stories, than 1?

$F=ma$. Falling from any distance, mass stays the same, and acceleration due to gravity stays the same. So, why does it hurt more, the longer you fall?
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1answer
39 views

Proton-Uranium collision

I am looking for references or numbers regarding what happens when one bombards Uranium with Protons. In particular: How to calculate how often does a collision occurs? Can a collision lead to a ...
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2answers
57 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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2answers
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Inelastic Collision and Energy

How is is possible for momentum to be conserved and for KE to not be conserved? Momentum is related to velocity and velocity is related to KE, therefore if KE was lost, how can the system have the ...
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0answers
34 views

Coefficient Of Restitution of Two Balls With Different Elasticities

In a computer program, I need to simulate the collision of two balls with different elasticity values given between 0.0-1.0. I looked for a formula to derive restitution coefficient from elasticity ...
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1answer
50 views

Why two colliding bodies exert varying forces on each other during the course of their collison?

Suppose a bat hits a ball .What is the explanation of why the force is not constant during the course of the collison. At certain instants both ball and bat exert varying degrees of force on each ...
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3answers
1k views

Why don't protons just bounce off each other in the LHC?

Ok, this might sound like a silly question, but I was wondering, when particles (e.g. protons) are smashed together in the LHC, why do they break up into dozens of other particles, as opposed to just ...
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1answer
72 views

Newton's Third law of motion: A hammer hits a wall vs. hits a tire

When we hit the wall by a hammer, Newton’s third law says that hammer applies force on the wall (action) and wall applies force on hammer (reaction) equal in magnitude but opposite in direction ok ...
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1answer
55 views

Newton's law for rigid bodies

Is newton's third law valid for rigid bodies? Say, if we have a bullet hit on a rod which is vertically placed on a rough floor. Friction is just sufficient sp that the rod rotates and does not ...
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1answer
44 views

Average force for repeated elastic collisions

I was asked to compute the average force exerted by a rigid spherical ball (mass $m$) on the floor over time $t \rightarrow \infty$, in a situation where the ball is dropped vertically from a height ...
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1answer
62 views

Two spaceships on collision course with cannonballs

Imagine two spaceships with a cylinder shape, travelling next to each other at the same speed. 4 cannonballs are exactly in their travelling path and they are about to get hit by them. One of the ...
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1answer
104 views

Is my proof of the thought experiment that Walter Lewin proposed in lecture 16 valid?

A tennis ball bounces off a wall elastically. The momentum of the wall changes, but the kinetic energy of the wall remains zero. How is that possible? Walter Lewin Lecture 16 - Ball bouncing on ...
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How to explain the momentum exchange of two solid particles collision at molecular scale?

Here is my question: assume two solid sphere collided to each other in vacuum, at macroscopic, it can be explain by Newton's law. But at molecular scale, does the surface atoms touch to each other or ...