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

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Inelastic collisions

During inelastic collision the kinetic energy does not remain constant. In many texts, I have seen it is because there is loss in energy from the system. If there is loss in energy, then how can mass ...
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Relativity collision problem [closed]

Here is the problem: A body of mass m (I assumed this is rest mass, but not 100%), and momentum p(subscript m) collides with a stationary particle of mass M. Find the available energy in the CM frame....
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Conservation of angular momentum in a collision

Suppose I have a stick hinged to a pivot and it is released from its horizontal position and just after it becomes completely vertical, it strikes a ball completely stationary as in the given figure ...
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62 views

How can we solve 2D rigid body collision? [duplicate]

I know that usually collision with velocity collinear can be solved by simultaneous equations of both conservation of energy and linear momentum. But my question is when 2D velocity is encountered, we ...
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6answers
136 views

How is momentum conserved when is is only dependent on mass and velocity, and so many other factors come into play?

I've been trying to get a good grip on the difference between conservation laws. Momentum is particularly tricky, I don't understand how quantities like $m\mathbf v$ can be conserved when other things ...
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1answer
52 views

How do I solve for $v_2$ where $mv_1^2 + MU_1^2 = mv_2^2 + M U_2^2$ and $MU_1 - Mv_1 = MU_2 - mv_2$ by eliminating $U_2$?

I was trying to solve the head on collision slingshot problem where the rocket moving with speed $v_1$ approaches a planet which is moving with speed $U_1$. I wanted the final speed of the rocket ($...
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25 views

Does final velocity after collision depends only on temperature change

An inelastic collision causes translational kinetic energy to be transferred into vibrational kinetic energy. Total kinetic energy is conserved. We measure the decrease in translational kinetic energy ...
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1answer
26 views

elastic collission

During an elastic collision some of the macroscopic kinetic energy is transferred to kinetic energy of the microscopic parts of the colliding bodies. The momentum is conserved, so the sum of the ...
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67 views

Plastic deformation energy dissipation due to inelastic collision

I have been attempting to determine an analytical expression for the coefficient of restitution (or any similar collision parameter) for an inelastic collision. So far, I've looked at Hertzian contact ...
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2answers
91 views

Where all those particles come from - proton proton collision

I was reading an article about the "Higgs factory" China is planning to build and it got me thinking about what happens when two protons collide. I am an engineer so I have a good understanding of ...
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3answers
107 views

Head-on collision between two neutrons

If two neutrons were set to collide head-on, being electrically neutral: Will they feel each other's presence due to electrostatic interaction between quarks of approaching neutrons? When they ...
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1answer
42 views

New direction vector after collision of spheres [closed]

I have a volume in 3-space in which random spheres are spawned in motion. They have the following attributes to them: position known (in three axes) a direction vector (in three axes) a scalar speed ...
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53 views

Elastic Collision of Infinitely Large Body and an Infinitely Small Body

So I guess this is a somewhat conceptual question. There are two bodies, one with a mass $m$ that is so light it is massless and at rest so $v_{_i1} = 0$ And the other with mass $M$ that is almost ...
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1answer
37 views

Momentum equation in collision of a particle and a droplet

When a solid particle which moves with a constant velocity has a head-on collision with a water droplet, at the exact moment of collision, a sudden decrease happens in particle velocity, and then ...
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4answers
255 views

Why the round trip instead collision time?

From Newton's second law, the $\Delta t$ is defined as the collision time, but why in this case, it can be assumed to be the value of time between successive collisions on 1 wall? If I have an ...
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2answers
131 views

What happens when two bodies collide in a dynamics point of view?

I'm a high school student learning about energy and momentum. What confuses me is the things with elastic and inelastic collisions. I completely (in my opinion) understand those concepts in energy ...
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2answers
130 views

What makes objects fly out of bike basket?

When riding a bike on a bumpy road, objects (let's say, a baseball weighing 150 grams) sometimes fly upwards and out of the basket. However I cannot seem to be able to explain this physically. ...
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0answers
37 views

kinetic energy of flowing fluid

When a quantity of fluid (let's say equal to volumetric flow rate Litre/s) collides during a second with an object, do all the molecules of this quantity collides with it? I am asking this question ...
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1answer
34 views

Rigid Balls aligned along a line in vacuum

Recently I've been trying to visualize a situation where i have these really rigid identical balls aligned along a line so close to each other in vacuum.Now if I were to apply an impulsive force to ...
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2answers
180 views

Elastic collision between two circles [duplicate]

I am trying to calculate the final velocities of two equal mass 2-dimensional circles after an elastic collision. I have tried to figure it out using formulas I know from high school physics, but ...
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0answers
8 views

Discrepancy of capture from 2p+1 state to 2p(+-1)

In the (nlm) characterization of hydrogenic orbitals. Consider the collisions H+ + H(2p+1) ---> H(2p-1) + H+ H+ + H(2p+1) ---> H(2p+1) + H+ where an electron capture has ocurred. Should the ...
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1answer
25 views

Coefficient of restitution belongs to kinetics and not to kinematics?Reason

The Coefficient of restitution is defined as $$e=\frac{v_2-v_1}{u_1-u_2}$$ $$v_2\to \text{final velocity body 2}$$ $$v_1\to \text{final vel of body 1}$$ $$u_1\to\text{initial vel of body 1}$$ $$u_2\...
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2answers
180 views

Is the reaction force for a stone hitting a wall infinite?

Let us assume a rigid stone which moves in empty space with a constant speed of $v$. (Or in the air with no friction and drag or you can imagine a free fall with friction). This stone hits a rigid ...
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2answers
52 views

Is Buoyant force a reaction?

When we fall on water. The surface molecules are pushed down and as a consequence molecules below the surface molecules and molecules beneath them and so on are also pushed down. Some of them are ...
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2answers
65 views

Energy release on impact

I was watching this video from a video game showing a space ship travelling towards a planet at 22% the speed of light. The ship system pulls the ship out of this "quantum travel" just in time to ...
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2answers
186 views

What exactly will happen if a small planet collides with earth

This is a video of a simulation of Ceres (a dwarf planet) hitting Earth at 2000km/s. What strikes me the most, is how fast the shockwave is moving. It takes about 6 minutes for the shockwave to pass ...
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2answers
202 views

What happens if a motorcycle going at 50mph crashes head into a car going at 60mph? [closed]

I wonder if a motorcycle (going at 50mph) crashes into a car (going 60mph), what is the damage that motorcycle will experience? Here's a diagram that shows what I've in mind: ...
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2answers
118 views

Conservation of Mechanical Energy Before and After Impact of a Hammer

If a hammer does work by driving a nail into a wooden board, how does the mechanical energy from right before the hammer hits the nail compare to the mechanical energy after the nail has been driven ...
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1answer
40 views

Conservation of momentum in inelastic conservation

Why does momentum and velocity change along contact normal but not contact tangent In in elastic collision? Suppose a ball strike an inelastic surface. It's velocity component does not change along ...
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2answers
88 views

How does general relativity explain the impact force after radial inward fall toward Earth?

I understand that, in the context of the Schwarzschild spacetime (General Relativity), a radially inward falling observer follows a time-like geodesic with zero four-acceleration. There are no forces ...
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109 views

Glancing collision question

Can someone explain the energy loss in a glancing collision to me? And how this compares with head-on collisions. I know head-on collisions are when objects rebound on straight line paths that ...
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1answer
25 views

For elastic collisions, can I transfer mass to velocity?

I think my teacher said that because the momentum is the same if you multiply/divide mass and velocity by the same factor, you can make the masses equal and then do a shortcut. Is this right?
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1answer
43 views

Impact on landing with forward motion vs straight down

A skateboarder ollies down a set of stair. Is the impact when landing less than if dropped straight down from the same height?
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Are the effects of faraday's law of induction worth considering in this experiment?

In my intro to physics lab at uni, we did an experiment where we were supposed to measure the amount of kinetic energy and momentum before and after collisions between two carts. For some reason, ...
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1answer
92 views

How to conserve angular momentum?

If i want to conserve angular momentum from the point of contact of the solid sphere and the ground how should I do it? I know we can use $mvh = I\omega + MvR$ ,if the collision is elastic. But in ...
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49 views

two sphere collision, distribution of KE

If we have two glass balls of exact same mass and size. We tape to the first one a very little piece of titanium facing the other sphere and we collide the two spheres at the same speed. The question ...
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2answers
180 views

What happens to the kinetic energy of a system in a non-elastic collision? [duplicate]

I know that the kinetic energy of a system is NOT conserved in a non-elastic collision. But energy is supposed to be conserved, so where does all that energy go? Is it transformed into other forms ...
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2answers
75 views

Heat produced in collision [closed]

A 5-gram marble is moving at 5 m/s [N] collides with a 2-gram marble moving at 3 m/s [N]. Final velocity of 2-gram marble: 7 m/s [N] How would I find the amount of heat produced in this collision? ...
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1answer
77 views

Understanding elastic collisions of objects with the same velocities

I am having trouble understanding the following statement from my book: The law of cosines tells us that if the sides of a triangle obey the Pythagorean formula, they must form a right triangle. ...
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5answers
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How does Newton's third law apply to an object interacting with air?

We all know that if I punch the wall with $100\,\mathrm{N}$ force, the wall pushes me back with with $100\,\mathrm{N}$ and I get hurt. But if I punch air with $100\,\mathrm{N}$, does air punches me ...
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1answer
41 views

What is happening from electro-magnetic point of view when a proton and an anti-proton annihilate?

Purely electro-magnetically before a proton (+) and an anti-proton (-) annihilate each other /assume they do/, they form a dipole. What happens after that? In other words, what does an external ...
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1answer
46 views

I do not know whether i have solved this correctly. Can anyone help? [closed]

A cart is moving along the $x$-direction with a velocity of $4 \;\mathrm{m/s} $. A person on the cart throws a stone with a velocity of $6 \mathrm{m/s}$ relative to himself. In the frame of reference ...
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1answer
234 views

Why does the rule that elastic collisions are at 90 degrees in 2 dimensions not apply?

When one object collides with another object of the same mass in a 2D plane, we know that we can derive that the angles that the objects leave the collision at add up to 90 degrees in a perfectly ...
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2answers
68 views

Why time of flight remains same for a projectile even though collision takes place?

Why time of flight remains same for a projectile even though collision takes place ? Suppose a ball is projected with some velocity V with some angle θ the the time of flight is T. Now if another ...
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1answer
109 views

Understanding $F=ma$

I know the formula F=ma, but I truly need to understand its implications. Take this scenario for example, we have two bullets exactly the same weight and size (identical to each other). Lets assume ...
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2answers
211 views

Problem regarding bullet penetration [closed]

Which property remains constant when we say that bullets are penetrating the wall? I mean is the resistive force always constant for a given wall (assumed stationary and immovable) irrespective of the ...
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1answer
718 views

How do I derive the formula of coefficient of restitution?

I have learnt in collision mechanics about the term Coefficient of restitution, $\mathrm{e=\frac{v_{2f}-v_{1f}}{v_{1i}-v_{2i}}}$. But the sad part is that, in my book only the formula is there. My ...
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59 views

Impact Time in Impulses

Impact time is said to be a key determinant in determining how much force is exerted upon a body. Because the impulse required to stop a falling block is the same regardless of what type of flooring ...
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1answer
73 views

Momentum conservation in a small time interval

I recently solved a problem in which I used the "fact" that the momentum is conserved just before and just after a collision between two (or maybe more) objects but I am not sure whether this is true ...