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

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Ratio of kinetic energy concerted to internal energy [on hold]

I need help with this question: Consider four identical cars. Two of them collide head-on when both are traveling at 34 m/s. The other two collide head on when both are traveling at 25 m/s. What ...
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1answer
29 views

Force of impact of a projectile [on hold]

I need to calculate the force of impact of a projectile on a target . The projectile has been fired at an initial velocity $U$ and an angle of departure $X$. The projectile is hitting the target at an ...
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2answers
33 views

Conservation of Momentum: Perfectly Elastic Collision, Example Problem

I am a middle school science teacher. I'm a little rusty on my physics knowledge, and I came across a question that I feel like I should be able to solve, but it also feels like there is a piece of ...
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1answer
27 views

Equations for a collision between two particles

Say I have two particles on a 2D plane, they have a x and y coordinate, a x and y velocity, a mass, a coefficient of restitution and a coefficient of friction. What formulae would I need to determine ...
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2answers
31 views

How do we prove that the initial velocity is equal to final velocity relative to centre of mass?

In elastic collision it is stated that the initial velocity relative to centre of mass is equivalent to final velocity of centre of mass of the same object. How do we prove that?
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1answer
31 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 ...
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3answers
57 views

Object falls and hits ground - which forces are involved to change its momentum?

When an object falls and hits the ground - which forces are involved to change its momentum? Should $m\vec{g}$ be taken into account of the forces that were involved in the change of momentum?
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15 views

Centrality analogue in proton-proton collision

If we look at ion-ion collisions one can represent most observables as a function of centrality (0-5% centrality class event etc.). Is there any possibility to introduce centrality analogue in ...
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0answers
45 views

What is the relationship between the Young's modulus of a material and the elasticity of a free fall collision

I'm coding a 2D physics simulator based around the Newtonian physics principles with some alterations due to computation limits and I am at the stage of creating a collision event between a planetary ...
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0answers
30 views

Ideal Bullet Block

What if in the experiment by Veritasium Bullet Block Explained, we used an ideal block and bullet, so that the collision is perfect elastic, and the bullet doesn't stick to the block after hitting it? ...
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0answers
32 views

Hitting the center of percussion

I have a couple of questions about the CP The formula is : $$b=\frac{L^2}{12A}$$ where b is the distance from CoG, therefore if L = 1 (and M = 12), the distance from the center of gravity be ...
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1answer
55 views

Elastic Collisions and Relative Velocities

In a 1D elastic collision, it is well-known that the relative velocities of the two objects (before and after the collision) are reversed. What is the extension of this result to 2D or higher? Is ...
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1answer
27 views

Definition of a symbol $s_{NN}$ appearing in particle physics

What is the meaning of $s_{NN}$ in particle physics? See e.g. here http://www4.rcf.bnl.gov/brahms/WWW/thesis/karabowicz_phd_thesis.pdf page 18 in the pdf. What is its relation to energy? I ...
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2answers
99 views

Is momentum conserved in the collision of a ball with a hanging rod?

Suppose we have a situation like A ball of some mass $m$ with some velocity collides with rod hinged at point $A$. Is momentum conserved in this situation? I know that hinge will give impulsive ...
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1answer
36 views

How to calculate the deceleration of two trains moving with the same velocity? [closed]

Two trains travelling on the same track are approaching each other with equal speeds of 40m/s. The drivers of the train begin to decelerate simultaneously when they are just 2km apart. If the ...
2
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2answers
51 views

Hockey puck collision [closed]

I have a homework question in which a sticky hockey puck traveling at constant velocity parallel to the side of the rink strikes a stationary puck and sticks to it. The angels between centres at ...
2
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0answers
50 views

Modelling an Inelastic Collision

I've attempted to model the inelastic collision between a moving mass and a large stationary object, e.g. dropping an ball on the floor, for analysing the approximate kinematics and heat dissipation ...
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0answers
50 views

Two cars colliding with different speeds

If I have one car travelling at 30 m/s and another travelling at 10 m/s both weighing the same amount, why is it that the car travelling 10 m/s would have more damage? According to Newton's third law ...
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1answer
21 views

A particle collides with another particle in an (infinitesimally long?) elastic collision, what is the resultant force?

When an object collides with another object in an elastic collision, the first object exerts a force on the second object (and vice versa); how do you calculate the force that the object experiences? ...
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2answers
241 views

Is it possible to determine the outcome of any impact knowing only the ratio of masses? [duplicate]

In elastic collisions in 2-D if two balls $A$, $B$ ($m_A = m_B$, $R = 1$) have equal mass we can determine in advance the outcome of the collision. If cue-ball $A$ impacts object-ball $B$ (at rest) ...
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1answer
43 views

Will the bouncing particle exert greater force on the surface?

Imagine elastic collision and no energy is lost from the system. A particle is emitted from the bottom of a box. The box is in inertial motion. The particle hits the top of the box and travels in ...
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2answers
99 views

Question about impulse and momentum

Check this question first please My question is: Why can't I use equations of motion to get the final speed after rebounding?Acceleration not equal to $9.8 \text{m/s}^2$ or the intial after ...
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0answers
87 views

Experiment to verify a spring constant

In my high school physics class, I had students do a Hooke's Law lab to measure an unknown spring constant. Once we compared everyone's data we came up with a class value for $k$ of 253 N/m. We then ...
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3answers
254 views

Does the stationary object deform more than the moving one after a collision?

Given two identical clay disks on an air track, one is stationary and another is moving at "high" speed. After colliding, does the stationary disk deform more than the moving one? If it matters, the ...
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0answers
31 views

Can a projectile moving at supersonic velocities leave a silhouette in whatever it hits?

I was recently reading this, and Floris's answer confirmed my knowledge that the information of an collision travels at the speed of sound. While I was thinking about that, my mind wandered and I ...
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3answers
103 views

When we catch a falling object, where does its kinetic energy go?

Some of it is transformed into heat and noise, but where does the rest go? Further details: The object does not bounce off (e.g. a sack of rice marble ball). The hand remains completely static ...
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59 views

Speed of a magnet

What is the speed of two magnets during the congruent moment of their attraction? Theoretically, could a large enough magnet attract a significantly smaller magnet at near the speed of light? In ...
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2answers
119 views

Force of a Train

Imagine that there are two trains and the first train is twice as long as the second train. They have the same mass per unit length and they are traveling at exactly the same speed. If the first ...
3
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1answer
35 views

Can the speed of a vehicle be determined based upon the extent of injuries to a pedestrian?

While driving at night in a Prius, at varying speeds of 5-20 MPH in heavy, stop-and-go traffic on a 4 lane city street, two pedestrians in dark clothing were struck (not in a crosswalk). One died of ...
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1answer
74 views

Prove the relation between relative velocity ,momentum and energy

In Chapter 8 of F.Mandl's book Quantum field theory, during the derivation of the differential cross section, the following relation is used: $$E_1E_2v_{rel}=\sqrt{(p_1p_2)^2-m_1^2m_2^2} \,\, ,$$ ...
2
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1answer
81 views

Relativistic Kill Vehicle

What would happen if a significantly supra-molecular object (say ranking from grams to low kilotons) would be accelerated to relativistic speeds (>.10 c) such that its worldline would intersect with a ...
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3answers
67 views

Why doesn't an object that collides with one that is at rest just do a 180?

Newton's third law says "for every action, there's an equal and opposite reaction." So why is it, say, that when a pool/billiards ball hits the wall of the table, the ball doesn't just turn around?
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3answers
81 views

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

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 ...
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2answers
55 views

Domain of different types of collision?

Can anyone tell me why elastic collision occur between atomic particles? inelastic collision occur between ordinary objects? perfectly inelastic collision occur during shooting? ...
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2answers
52 views

Factors on which Coefficient of restitution depend

What are the factors on which coefficient of restitution depend? What is the reason for more coefficient of restitution of two glass balls (0.95) than for two lead balls (0.20)?
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2answers
71 views

Playing catch in space?

I was thinking about this on the bus (exam this week :P). What would happen if two people played catch in outer space? Lets say person A and B are in space at rest, A throws a mass m at B, what ...
2
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2answers
94 views

Why is there conservation of kinetic energy in elastic collision and not in inelastic collision?

Why is there conservation of kinetic energy in elastic collision and not in inelastic collision? What would be the difference that lead to conservation of kinetic energy in elastic collision and not ...
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7answers
3k views

Ball flying towards me or me flying towards ball

Suppose a ball is flying towards me at a speed of 10m/s and that, on impact, I feel "x" amount of pain. If, instead, it was me flying towards the ball at the same speed, with all other conditions ...
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1answer
36 views

Algorithm to determine impact result (on variety of materials) [closed]

There are two bodies. One is small and moving with a specified speed (projectile), second is several times larger (target). Then projectile hits the target. We know the projectile speed and material ...
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64 views

Throwing a baseball against the back of a car [closed]

We, some fellow students and I, are trying to figure out what to. But we simply do not know which formula to use at question a. We found the following: $\Delta P=(2mv_{ball,i}M)/(m+M)$ Could someone ...
3
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3answers
272 views

Impulse and force in a karate chop, can we maximize force minimizing the time of impact?

I have heard that we can maximize the force by minimizing the time of impact in a punch. If that is true, the paradox is if we increase the time of contact with the same amount of force still we ...
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1answer
66 views

Why does accounting for direction give the wrong result for a bouncing ball?

This a conservation of momentum problem, gathered from an old textbook. I thought it would be simple, but I seem to be goofing up somewhere in my basic conceptual understanding. PROBLEM: A 1.0 kg ...
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3answers
88 views

How can the bodies attain same velocities during the max. deformation during collision?

My book writes: Collision between two bodies is almost similar to the case where there is a spring between the two colliding bodies. At the instant they come into contact , the rear ball has a ...
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1answer
144 views

Work-Energy theorem vs conservation of mechanical energy? [closed]

Bodies A and B are moving in the same direction in a straight line with constant velocities on a frictionless surface. the mass and the velocity of A are: 2kg and 10m/s. The mass and the velocity ...
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1answer
35 views

Will the particle reach other end?

I place a container at rest in vaccum and filled it with air (STP conditions). Suppose a moving particle(sphere of dia 2mm) is placed at one end of the container without disturbing anything, will ...
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1answer
84 views

Conservation of momentum 1-D problem: track is not level

This problem is a standard kind of 1-D problem. You have 2 equal carts approaching each other and collide on linear air track. BUT the person setting up the track did NOT do a good job at making the ...
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1answer
85 views

Collisions of celestial objects

When massive, spherical celestial objects collide, how long does it take for the objects to coalesce into a new, larger, spherical entity under the influence of gravity? Examples of the above:- ...
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1answer
43 views

What matters more in the strength tester game at a carnival, momentum or force?

A buddy and I were arguing over which matters more in the strength tester game (assuming the same accuracy of the hit): 1) momentum or 2) force. He was arguing that if you swing the hammer directly ...
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1answer
56 views

Is change in kinetic energy invariant?

Consider the inelastic collision between two bodies. This question follows on from this: Is the coefficient of restitution frame independent and energy conservation?. One of the answers to this ...
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150 views

Where does the force to stop a constant velocity object come from?

If a ball hits a wall at a constant velocity, it will slow down and eventually come to rest. Since the ball was at constant velocity, it was not accelerating, and so there was no force. Also, the ...