Questions tagged [collision]

This tag is for questions relating to collision which is the interaction between two or more bodies that results in physical contact and an exchange of momentum between the bodies involved. When it happens, kinetic energy is often exchanged between the molecules’ translational motion and their internal degrees of freedom.

A collision (also called impact) is short duration interaction between two bodies or more than two bodies simultaneously causing change in motion of bodies involved due to internal forces acted between them during this. Collisions involve forces (there is a change in velocity ). The magnitude of the velocity difference at impact is called the closing speed. All collisions conserve momentum. What distinguishes different types of collisions is whether they also conserve kinetic energy.

The line which is common normal for surfaces are closest or in contact during impact is called the line of impact. This is the line along which internal force of collision acts during impact and Newton’s coefficient of restitution is defined only along this line.

Classification: There are basically two types of collision.

  • Elastic collision: The type of collision in which both the momentum and kinetic energy of the system are conserved is called elastic collision. The collision between subatomic particles is generally elastic. The collision between two steel or glass balls is nearly elastic. In elastic collisions, the forces involving are conservative in nature.

  • Inelastic collision: The type of collision in which only momentum is conserved, not kinetic energy is called inelastic collision. Most of the collisions in daily life are inelastic in nature.

The magnitude and direction of the velocity of the colliding bodies may change in a collision. The force involved in collision acts only for a very short period of time. We come across many examples of collision daily. The coins of a carom game colliding with one another or collision between vehicles in road etc, are examples of collision

References:
Collision
Collisions

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How long does the contact between a free-falling rigid sphere and the ground last in a perfectly elastic collision?

It seems to me that this time is finite, although it seems infinitely small, but if it is finite, is it also identical for any perfectly elastic collision? What should I know about this time?
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Physics engine - collisions

I'm working on a 2D physics engine somulator and I want it to be very accurate on a Physics point of view. Currently I'm making some researchs about how rigid body collisions may be calculated, and I've found this page, that presents the following…
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Are there perfect elastic collisions in Nature?

Can we find at any level, molecules, atoms, particles etc., a perfect elastic collision? If not, what is second best? EDIT: At macroscopic level what is the most elastic material and the highest CoR recorded? Do you know of a record of a longest…
bobie
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Is there any way to know if a collision will be elastic or inelastic before the collision takes place?

Pardon me if this is a duplicate. Say I have two objects that are heading towards each other (one going to the right and the other heading left). Both have a constant mass (let's say 2kg and 4kg respectively) and velocity (5m/s and 3m/s) before the…
zxcv
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Collisions of milk

I am studying collisions of two thin sheets of whole milk with each other versus two thin sheets of skim milk with each other. The coefficient of restitution of whole milk is significantly higher than that of skim milk. I'm thinking that upon…
rdemyan
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Can we find coefficient of restituion using Young's Modulus

Suppose a moving body collides with another body and we are given the Young's Moduli of the two bodies. Is there any method to find their final velocities?
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What is the rebound angle of a circle striking a concave surface?

First, pardons to all because I don't have a physics background and I'm probably using laymans terms. What is the rebound angle of a circle striking a concave surface? Assume the simplest case: the circle (red) is not spinning the circle does not…
user50811
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what happens during collision at molecular level?

When two massive bodies collide we treat them simply by their mass interactions with momentum and energy conservations. Down at the molecular level it must be more like a field particle collision for the particles coming in close contact, why dont…
Rijul Gupta
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Equation for two particle elastic collision, both having velocity and size, in arbitrarily high dimension

Is there any theory about general particle elastic collision (both having velocity, different mass, and different size) in arbitrarily high dimension? I was thinking about conservation of momentum and energy, but I kind of confused myself. Since…
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Incident Angle of Impactor Against Ellipticity of Crater

Recent empirical results that I have produced by dropping balls into sand indicate that the ellipticity of a crater- i.e. the ratio of major axis diameter to minor axis diameter - varies linearly with the angle of impact of an impactor (the angle…
P0W8J6
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Summation of the velocities before and after an elastic collision

Suppose two particles of masses $m_1$ and $m_2$ with initial velocity $v_1$ and $v_2$ have an elastic collision. Let $v_1'$ and $v_2'$ be their new velocities. We know that $$v_1'= \frac{(m_1 - m_2)v_1 + 2m_2 v_2}{m_1+ m_2}, \quad v_2'= \frac{(m_2 -…
Pengfei
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Elastic collisions given mass and energy

If a stationary oxygen atom is hit head-on by a neutron, and the oxygen atom now has energy equal to say 20 keV, is there a way to calculate the initial energy of the neutron?
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Elastic Collision of a rod which can move and rotate with a particle obliquely

I am facing trouble with the following question A rod $AC$ of length $l$ and mass $m$ is kept on a horizontal smooth surface. It is free to rotate and move. A particle of same mass $m$ moving on the plane with velocity $v$ strikes rod at $B$…
Pink
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Collision between airborne stone and car

If two cars are driving with a certain distance from each other, and the tires of the first car makes a stone (from the asphalt) become airborne with a high velocity - towards the second car: The stone hits the windshield. Does the mass of the…
Erosennin
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Reasoning behind existence of fixed ratio of relative velocities of two bodies before and after collision for a certain combination of objects

Lets say two bodies experience head on collision with each other. It is said in my textbooks that it is found that the ratio of relative velocities of the two bodies before and after collision is fixed for a certain combination objects. But no…
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