What is Collisions: Definition and 706 Discussions
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word collision refers to incidents in which two or more objects collide with great force, the scientific use of the term implies nothing about the magnitude of the force.
Some examples of physical interactions that scientists would consider collisions are the following:
When an insect lands on a plant's leaf, its legs are said to collide with the leaf.
When a cat strides across a lawn, each contact that its paws make with the ground is considered a collision, as well as each brush of its fur against a blade of grass.
When a boxer throws a punch, their fist is said to collide with the opponent's body.
When an astronomical object merges with a black hole, they are considered to collide.Some colloquial uses of the word collision are the following:
A traffic collision involves at least one automobile.
A mid-air collision occurs between airplanes.
A ship collision accurately involves at least two moving maritime vessels hitting each other; the related term, allision, describes when a moving ship strikes a stationary object (often, but not always, another ship).
In physics, collisions can be classified by the change in the total kinetic energy of the system before and after the collision:
If most or all of the total kinetic energy is lost (dissipated as heat, sound, etc. or absorbed by the objects themselves), the collision is said to be inelastic; such collisions involve objects coming to a full stop. An example of such a collision is a car crash, as cars crumple inward when crashing, rather than bouncing off of each other. This is by design, for the safety of the occupants and bystanders should a crash occur - the frame of the car absorbs the energy of the crash instead.
If most of the kinetic energy is conserved (i.e. the objects continue moving afterwards), the collision is said to be elastic. An example of this is a baseball bat hitting a baseball - the kinetic energy of the bat is transferred to the ball, greatly increasing the ball's velocity. The sound of the bat hitting the ball represents the loss of energy.
And if all of the total kinetic energy is conserved (i.e. no energy is released as sound, heat, etc.), the collision is said to be perfectly elastic. Such a system is an idealization and cannot occur in reality, due to the second law of thermodynamics.
Homework Statement
A block of mass M is compressed a distance x against a spring which has a spring constant k.
When released, the block slides along a frictionless surface until it undergoes a completely inelastic collision with a block of mass 3M. The two blocks travel together some distance...
Homework Statement
I am to find the mean time between collisions of electrons in a wire and am having a difficult time manipulating equations with known variables. I am given values for E, J, n and rowe.
Homework Equations
v = (qT/m)*E
rowe = E/J
J = nqv
The Attempt at a Solution...
Two trucks, one twice as heavy as the other, collide head on (assume it's one dimensional and easy ;) ) and the collission is perfectly inelastic. If it was perfectly inelastic there would be no kinetic energy left, and therefore no velocity. How do the trucks manage to conserve momentum by...
assuming collisions are elastic...
right 5 equal masses, if you displace the first ball then you observe balls 2-4 stationary and 5 moves off with equal speed to the right, as all the momentum and energy is passed to ball 2, ball 1 stops, ball 2 then passes all its momentum and energy to ball...
Hello. I am trying to better understand relativistic inelastic collisions for objects with mass and the setup for them.
Let's say that I have two objects with different masses, one of which collides with the other, which is stationary.
Without even specifying a reference frame, can I solve...
I am aware that the LHC accelerates subatomic particles to just under the speed of light then smashes them together. However, at the time of collision, would this mean that the combined speed of the impacting particles is almost two times the speed of light? Or are the particles individually...
A few questions...
1) Does an electron have to have the exact amount of energy to cause excitation, or can it have more (i.e. can the eV of an incoming electron be equal or more than the excitation energy required for excitation of an atom to happen)? If so, does the electron that collided...
Why when a boxer, mma artist, football player, or any other athlete makes a collision such as a punch, kick or tackle we measure that using Force units (pounds or kilograms)?
Would not make more sense use Energy units or Impulse units?
I was just watching espn and they say a football...
Hello,
I was thinking about colliding balls and the conservation of momentum.
If a ball weighing 10kg traveling at 10m/s collides with another stationary ball weighing 5kg, then the two balls should be moving with some velocity so that the overall momentum is 100kg m/s
My question is what...
About collisions of macroscopic objects:
- Can they be perfectly elastic in reality? If not is this a consequence of the 2nd thermodynamic law?
About microscopic collisions (between molecules, atoms or elementary particles)
- Can they be perfectly elastic? A collision between two...
I'm doing a research project on collisions and I've come across a part of my theory that requires solutions to coupled damped oscillators.
Could anyone please refer me to some text on 2 coupled damped oscillators which isn't extremely math heavy and has conceptual explanations of the...
Does it exist an accurate model about what happen when two stellar bodies collide?. I'm referring to the kind of collision between neutron stars, white dwarfs. I was wondering if that collision could produce a new kind of object. For example: a white dwarf into a neutron star, and a neutron star...
Homework Statement
A particle of rest mass m_1 moving with velocity u_1 along the x-axis collides with a stationary particle of rest mass m_2 stationary along the x-axis. If subsequently the particle with rest mass m_1 moves in the direction making an angle of 60^{o} relative to the x-axis...
Homework Statement
Derive formula for elastic collisions in one dimension, unequal masses target at rest.
i am having trouble acquiring the same formula that the book gives me, please tell me where my algebra is incorrect...
i need to be able to derive these formulas properly because...
1) A tennis ball of mass mt is held just above a basketball of mass mb.
Their centers are vertically aligned. They fall through a height h, then there's an elastic collision with the ground which reverses the velcoity of the basketball while the tennis ball is still moving down because the...
Hi - I got into a debate with a friend of mine today and was wondering if you could shed some light on this topic.
Two identical cars are moving at, say, 30 mph and hit head-on. There is some force and momentum involved there...
Would they hit with the same force and/or momentum as an...
Homework Statement
There are 3 blocks, A B and C, arranged left to right. blocks A and C have masses of m and block B has mass of 2m. block A heads toward the other two with velocity v. determine the final velocity of each block after all subsequent collisions. assume all collisions are...
In a particle accelerator I.e. LHC a beam of protons are moving past each other and produce an est 1billion collisions per sec. Here's a question about that and the result of such collisions. please bear with me as this may seem a simple question. how do we know exactly that the results recorded...
I want to know the ways newly created particles are detected during collisions such as in LHC or Fermilab, i.e either they check the EM force, electric charge being observed or other things...
Hello everyone,
Quick question: Which particles are colliding at the LHC and why?
All I know is that proton-proton collisions are explored as well as heavier nuclei such as gold (Au) and lead (Pb) to research the quark-gluon plasma state.
-Hioj
Hello - I am pretty sure this is correct but there is no answer for me to check. My friend (who is a lot smarter than me :P ) got a different answer entirely. Is the following answers correct?
Homework Statement
Puck A has a mass of 0.0300 kg and is moving along the x-axis with a velocity of...
If one observer in an inertial reference measures a collision to be elastic, then all observers in an inertial reference frame will measure the collision to be elastic - can this be explained with the conservation of energy? What exactly does the conservation of energy principle say in regards...
How will the space vehicles avoid satellites and those kind of things, when they are on a journey? I haven't seen any shuttle hitting a satellite/ even satellite(not geostationary) colliding on each other?
What's the reason of it not happening?
My friend is programming a curling application for the Android. He needs a way of calculating the results of perfectly elastic collisions in 2 dimensions with perfectly round objects (curling stones in this case, naturally).
I know what the basic formula for the conservation of momentum is for...
First off, I'm not in any way anti-LHC. Quite the opposite to be honest. Even so, this speculative disaster scenario (vacuum bubbles) have caught my attention latelly, and I haven't been able to let go off it. Mostly because I find the otherwise brilliant LSAG-report (both actually) to be quite...
Homework Statement
http://img834.imageshack.us/img834/8045/questuinfunny.jpg
The Attempt at a Solution
[PLAIN][PLAIN]http://img824.imageshack.us/img824/3619/funnyquestion.jpg
Homework Statement
A radioactive nucleus at rest decays into a second nucleus, an electron and a neutrino.The electron and neutrino are emitted at right angles and have momenta of 9.3x10^23kg*m/s and 5.40x10^23kg*m/s, respectively. What are the magnitude and direction of the momentum of the...
Homework Statement
Billiard ball A of mass mA= 0.400kg moving with speed vA=1.80m/s strikes ball B initially at erst, of mass mB=0.500kg.As a result of the collision,ball A is deflected off at an angle of 30.0degrees with a speed v'A=1.10m/s. Taking the x-axis as the original direction of...
The science series currently on TV in the US called WORMSHOLES, narrated by Morgan Freeman (the actor) has a number of recent some new ideas. (Very worthwhile series, by the way.)
The show last night discussed dark matter and dark energy and referred to a distant pair of galaxies colliding...
Homework Statement
Daisy (65.0kg) skates on ice at 4.5m/s to greet her friend (75.0kg), who is standing still, with open arms. As they collide, while holding each other, with what speed do the both move off together?
Homework Equations
MaVa+MbVb / Ma+Mb
The Attempt at a Solution...
how fast are the particles in the 2 beams of a Pulsar traveling? and what happens when two of those beams intersect? do those particles collide at extremely high velocities like in particle accelerators?
Hi, I'm helping my friend with a space combat game he is programming. What I'm trying to figure out is how to model the collisions between spheres in 3D.
So far I've figured out how to calculate final velocities of 2 colliding spheres using conservation of linear momentum. I found a...
Ok so I'm writing a 3D game that uses impulse to determine how things behave when they collide. In this game I have two cubes. Now the shape of each cube is defined by 9 spheres, sort of like this:
http://mark.reid.name/images/figures/high-dim-3d.png
Though in my game the middle sphere is...
Homework Statement
Consider an elastic collision of two particles in the centre of mass frame. Briefly explain why the speed of EACH particle after the collision is the same as before the collision.
(FYI this is exam revision so it isn't worth any marks)
The Attempt at a Solution...
Homework Statement
Which of the following statements is true for collisions?
a) Momentum and Kinetic energy are always conserved in collisions.
b) Momentum can only conserved in elastic collisions.
c) Kinetic energy is conserved only in inelastic collisions.
d) Only kinetic energy can be...
Homework Statement
Two blocks are on a frictionless ramp. The first block has a mass of 5.00kg and is released from the top of the ramp 5.00m. It has a magnet on the front with the north pole facing out. The second block is at rest at the bottom of the ramp and has a mass of 10.00kg. The...
Hi,
Would anyone be able to explain the main differences between the effect of electrons and photons colliding with atoms in the ground state.
As far as I understand they are very similar as both cause excitation and in some cases ionization.
Any help would be greatly appreciated.
Dave
Homework Statement
A 3 kg steel ball strikes a wall with a speed of 10 m/s at an angle of 60° with the surface. It bounces off with the same speed and angle. If the ball is in contact with the wall for 0.2 s, what is the average force exerted by the wall on the ball...
I am unaware of any other method for analyzing elastic collisions other than applying both conservation of momentum and conservation of energy. Since Newton didn't have conservation of kinetic energy to use as a tool was he unable to analyze elastic collisions?
PS
In the Scholium at the end...
Homework Statement
A nuclear reactor (see below) contains nuclei that fission when bombarded by slow neutrons. The fission reaction produces fast neutrons which need to be moderated (i.e. slowed down) in collisions before they can cause further fissions. In this problem we consider a reactor...
Homework Statement
Consider the following reaction that is possible when a proton (p+) collides with a photon (γ):
p+ + γ → ∆+.
Suppose that the photon is a cosmic microwave-background (CMB) photon of energy 2.3 × 10−4eV. Calculate the minimum energy that the proton must have for this...
A particle accelerator collides 5000 GeV muon+ with 5000 GeV muon- particles, producing two massive particles in the final state, one with a mass of 800 GeV and another particle with unknown mass m.
a) write down the initial and final state momentum vectors
b) by using the conservation of...
If positive charged particles curve in the presence of a magnetic field does that mean the particles colliding in ATLAS create magnetic fields? I ask this because some of the detected particles curve perpendicular to the collision in ATLAS. From what I observed the trajectory maintains a...
Hi, I am in the process of doing up a physics simulation in 2D OpenGL where balls bounce around the place, colliding with planes and themselves.
I have everything done except the collisions between the balls themselves. I can detect a collision but I am finding it hard to find any sort of...
Homework Statement
How do you show that in the non-relativistic case, if KE is conserved in a collision as viewed in one frame, then it is conserved in all other frames moving with constant velocity?
Homework Equations
The Attempt at a Solution
Not sure what to do...
thanks
This seems like such a simple question and I feel like an idiot asking it, but here goes:
If we have a hydrogen atom (not molecule) at "rest" and we shoot an electron at it with a certain known energy, what could happen?
To me, it seems as though there are two distinct outcomes; either the...
When a mass collides with a spring attached to a different mass; why is the maximum compression of the spring when the velocity of both masses is the same? (Spring is massless and surface is frictionless to make things simpler)
My mechanics teacher told me this when I was solving (or rather...
Homework Statement
Two particle P and Q each of restmass m0 and moving in collision course at 2/3c in the laboratory frame of reference.
In the same collision but in particle P's frame of reference, P is at rest.
Homework Equations
As the total energy of the particles depends on the frame...
Homework Statement
Two particle P and Q each of restmass m0 and moving in collision course at 2/3c in the laboratory frame of reference.
In the same collision but in particle P's frame of reference, P is at rest.
Homework Equations
As the total energy of the particles depends on the frame...