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

learn more… | top users | synonyms

-1
votes
0answers
17 views

How to Determine mass of the ball that is being hit by another ball on the pendulum? [on hold]

I know mass of ball on the pendulum M, initial height of that ball h+H, height of the table on which pendulum is and I know how far away from the table the ball mass m falls. I have the following ...
1
vote
2answers
279 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, ...
0
votes
1answer
41 views

Impulse of two different objects

I was running over a question, A collision occurs between particles A and B which are moving in opposite directions in the same straight line. The impulse on each particle in the collision is 2N.s, ...
5
votes
1answer
787 views

Moment of inertia of rotating particles in center of mass frame?

I am trying to simulate a collision between two molecules. I know the energy for every position/orientation, from which I can calculate the forces. The treatment is classical and the molecules are ...
3
votes
1answer
54 views

Collision between a “spring” and a particle

I am currently attempting to create a simple 2D physics engine, and I just need to know how to solve a certain collision. I have particles, and between any two particles, springs can be connected. ...
2
votes
2answers
70 views

Newton's Cradle: why does it stay symmetric? [duplicate]

How is it that always the same number of balls leave at the other end in Newton's cradle. I understand that the momentum needs to be conserved, but as momentum is defined as p=m*v couldn't you have a ...
0
votes
0answers
23 views

The geometrical-locus result of collision and fall

A classical momentum-conservation experiment follows about this way: On a table there is a sloped track and a ball is rolled down. At the bottom of the track, a second ball is at rest. The balls ...
2
votes
1answer
45 views

How can you find the impact necessary to change the direction of Earth's spin?

If an object the mass of the moon was to hit earth's surface at an angle that would be in the opposite direction of earth's spin, how can you find how much momentum the object needs to cause earth to ...
0
votes
2answers
39 views

Simple mathematical model for a bouncing ball

I started coding a physics program that simulates gravity - specifically a bouncing ball - and I've already learned a lot researching the topic but the bounce still doesn't look quite right. I need a ...
2
votes
3answers
1k views

What are the general solutions to a hard sphere collision? [duplicate]

Surely someone has found the solutions to the hard sphere collisions (in $n$ dimensions) of two bodies of mass $m_1$ and $m_2$, respectively--that is the resultant velocities (or momenta) of the two ...
1
vote
0answers
32 views

Colliding beams vs static target

In this problem I need to find the threshold energy of a positron-electron collision that creates a Z boson (the reverse of the following picture; Z mass 92 GeV) in two distinct cases: collision ring ...
6
votes
1answer
208 views

How do I describe and calculate the effect of an impacting object?

My lab studies the physiology of impact injury on biological tissues. I use a pneumatic cylinder to impart injury into a biological sample and then assess the molecular and physiological changes in ...
3
votes
2answers
51 views

$e^+e^-\to q\bar{q}$: Reconstructing $q\bar{q}$ energy and momentum

Question In a real collider experiment e.g. LHC / LEP how can one reconstruct the energy and momentum of the resultant $q\bar{q}$ pair produced from the process $e^+e^-\to q\bar{q}$? Specifically, ...
1
vote
1answer
39 views

Intuitive picture for Mandelstam $t$

In tree-level electron-positron scattering one has two possible channels corresponding to Mandelstam variables $s$ and $t$. The $s$-channel ist fine, there $\sqrt s$ is just the center of mass energy ...
3
votes
4answers
156 views

Collision paradox

Suppose an insect travelling south at some velocity, collides with a train travelling north at some other (opposite) velocity. The insect hits the front of the train, where it splats to an ...
1
vote
1answer
32 views

Perfectly elastic and inelastic collision of photon

I`m having some trouble understanding (and finding any relevant information) about the elastic and inelastic collision between a photon and a mirror in non-quantum machanical terms. When a photon hits ...
1
vote
1answer
72 views

Why a bullet leaves a hole on glass where stone makes scratch?

When we throw a stone it breaks the glass with scratches. But when a bullet hits the glass it leaves a small hole(not always) . I want to know the specific reason behind making hole and scratch.
0
votes
0answers
7 views

Head-on collision near lightspead [duplicate]

Assume two objects moving near light-speed (for this experiment let's say $0.9c$) towards each other. The speed is measured from an observation platform at the collision point (as I understood ...
0
votes
1answer
49 views

How do you determine which way two objects will travel after collision when given their respective masses and speeds?

I was practicing some Mechanics, and I came across a problem that involved an impact between two objects: I understand how to approach the question: Apply the conservation of momentum, and use the ...
0
votes
0answers
13 views

Simple deduction of differential cross section from total cross section

In Povh's book "Particles and Nuclei" we read the following: I simply cannot wrap my head around what happened from eq. 5.20 to 5.22. How did he deduce that the cross section for the scattering into ...
-1
votes
3answers
49 views

Change in linear momentum [closed]

Let A and B be to rigid blocks. A is stationary while B is moving with a velocity $u$. So if B collides with A. (These blocks are on a frictionless surface.) What would happen after B collides with ...
1
vote
2answers
111 views

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 ...
0
votes
4answers
104 views

Why don't two objects move with the same velocity after collision?

I have a problem with understanding the nature of collisions and their outcomes. From my understanding, I come to think that when a mass collides with another, both of them should always have equal ...
10
votes
1answer
533 views

What would the collision between a (large) solid planet and a gas giant be like?

Assuming a Jupiter-like planet and an Earth-like planet (Except, say... half the mass of Jupiter), what would happen when the two collide? For clarification: What would the actual collision be like? ...
2
votes
4answers
237 views

How is a ballistic pendulum affected by two objects with different masses?

Imagine that bullet A (made of lead) has twice the mass of bullet B It is shot at the same muzzle velocity as bullet B onto a ballistic pendulum; all other initial variables are the same: size and ...
0
votes
1answer
39 views

Momentum equation of a beam hitting a stationary target to create antiprotons

I'm struggling with the solution of a physics exercise which is to calculate the minimum energy needed to create antiprotons when a proton beam scatters on a stationary proton target: $$p + p ...
1
vote
1answer
34 views

Variation of Veritasium bullet block experiment

I'm new here. this is in reference to the video posted by veritasium on the bullet block experiment. i realise there is already a thread on this but i want to ask a variation of the question. so ...
1
vote
2answers
254 views

Why do particles of equal mass (with one at rest) undergoing elastic collisions scatter at only right angles?

This is from the Section 9.6, page 351 of "Classical Dynamics of Particles and Systems" by Thornton and Marion. By setting a up a system where mass 1 has initial momentum $m_1 u_1$ and mass 2 is at ...
0
votes
0answers
14 views

Momentum conservation problem, elastic collision [duplicate]

This question has got me thinking for a while now and I haven't been able to come up with any answer at all. I've done the basic conservation of momentum, kinetic energy but I have no idea how to ...
0
votes
1answer
45 views

What is the best way to calculate impact time with collisions?

I've been teaching myself physics and I've been wondering about the impact time in collision calculations. The scenario I've been using to learn is an object with a mass of 4000 kilograms colliding ...
1
vote
3answers
442 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 ...
0
votes
1answer
113 views

What will happen to the center of mass of the human body when a person carries a weight with one hand?

What will happen to the center of mass of the human body when a person carries a weight with one hand a briefcase for example. Wouldn't the center of mass move horizontally towards the side carrying ...
1
vote
1answer
28 views

Using the central equation for inelastic collisions entropy change

I have what appears to be a simple question but I seem to be missing something. Take a constant temperature system where a ball travelling at $5ms^{-1}$ strikes a stationary ball and sticks to it in ...
3
votes
2answers
153 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 ...
0
votes
2answers
178 views

In a CMCS 2-body system, why does the speed of the particles after collision stay the same?

A particle $m_1$ is traveling with velocity $v$ toward a stationary particle $m_2$. The velocity of the center of mass is given as $v_c=\frac{m_1}{m_1+m_2}v$. Changing to a moving coordinate system, ...
0
votes
1answer
42 views

Difference between sudden force and impulsive force? [duplicate]

What is the difference between a sudden force which continues to act on the body, and an impulsive force? What would be respective speeds of the body just after time= 0?
0
votes
2answers
154 views

Elastic collisions and 90 degrees angles [closed]

Why is it that if the angle between the two objects that collided together is 90 degrees then it must be perfectly elastic? Is there any theoretical proof other than convention?
-1
votes
1answer
49 views

The ratio of masses in an elastic collision [closed]

Two blocks of mass $M_1$ and $M_2$ moving along a 1-dimensional straight line with velocities $V_1$ and $V_2$, respectively, collide elastically. After the collision they move with respective ...
0
votes
1answer
23 views

When to consider friction as an impulsive force?

Suppose a ball obliquely strikes a rough horizontal surface then it experiences a frictional impulse and conservation of linear momentum cannot be done on the horizontal direction. Now consider ...
0
votes
1answer
60 views

Collision with a stationary Hydrogen atom [closed]

Can some explain me what happens when an electron or neutron collides with stationary Hydrogen atom? What are conditions for elastic and inelastic condition? For example, how to tackle following ...
0
votes
1answer
38 views

Calculating the Coefficient of Restitution Based on two Objects

The coefficient of restitution is calculated based on the velocities of objects before and after a collision: $$C_R = -\frac{v_{2f} - v_{1f}}{v_{2i} - v_{1i}}$$ The coefficient of restitution tells ...
1
vote
1answer
35 views

How do these particles sort themselves by size? [duplicate]

I have this bowl of sodium polyacrylate (Insta-Snow) that has been drying out for a few weeks. At this point it consists of solid pieces ranging in size from 3 or 4 mm across to much smaller ones ...
0
votes
1answer
19 views

Spheres collide with merry-go-round [closed]

Four spheres, with uniform densities $\rho_1, \rho_2, \rho_3, \rho_4$ and radii $r_1, r_2, r_3, r_4$, respectively, roll without slipping with constant velocities $v_1, v_2, v_3, v_4$ along tracks ...
0
votes
1answer
19 views

Physics of Auto Crashes and Airbag Modules

I recently saw a post (that was pretty old) asking why we don't consider the jerk function more often in sciences that deal with impacts or sudden accelerations. The general belief was that impacts, ...
3
votes
2answers
60 views

Does inelastic collision say the ball bounces back to you when thrown at an angle on ground?

I created a bounce simulation using exactly the formula from Wikipedia. The behavior I observe is not what I would expect in two cases: When two balls hit off-centre, they act the same as if the ...
0
votes
1answer
601 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 ...
0
votes
1answer
32 views

How do black holes join each other? [duplicate]

If black holes can swallow any object, and can radiate energy, then how could black holes join each other and can form bigger black holes?
2
votes
2answers
5k views

Inelastic collision and conservation of linear and angular momentum

Is it possible for two spheres (a & b) to have an inelastic collision with BOTH the total linear and angular momentum preserved? I'm doing some physics simulation of some spheres attracting each ...
-1
votes
2answers
78 views

How can work be done during collisions? [closed]

Consider a collision between two material points, with no external forces acting on the system. Linear and angular momentum of the system are always conserved, while the kinetic energy of the system ...
1
vote
2answers
88 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 ...