1
vote
2answers
47 views

Change of kinetic energy in a two particle collision

A problem I am working on proceeds as follows: A billiard ball of mass $M$ is initially at rest on a horizontal frictionless table. Another ball of mass $m < M$ and velocity $\mathbf{v}$ in ...
-3
votes
0answers
40 views

Conservation Laws and relativity [on hold]

A 50 kg meteorite moving at 1000 m/s strikes Earth. Assume the velocity is along the line joining Earth's center of mass and the meteor's center of mass. What is the gain in Earth's kinetic energy?
0
votes
1answer
26 views

Question on the negativity of the coefficient of restitution

I was trying to solve a Mechanics question on Momentum. Here is the question : Two small smooth spheres A and B have equal radii and have masses m and km respectively. They are moving in a ...
3
votes
4answers
290 views

If a truck collides with a car, can the truck experience a larger force?

I am confused, here is a question: A large truck and a mini bus both have same velocity V and they collide and stop. The collision lasts for 1 second. A) Which one of the two will experience ...
0
votes
0answers
18 views

Change in momentum [duplicate]

A cube has a side length of 20 cm. An atom in the gas moves around the cube as shown. It continually bounces off the four lateral walls of the cube. The atom has a mass of 6.6×10−27 kg. Because of the ...
1
vote
0answers
20 views

Collision (work energy and power) [closed]

A ball is allowed to fall from rest on a horizontal floor from a height of 10m If there is 20% loss of energy due to impact then after one impact ball will go upto?
0
votes
2answers
62 views

A spring with two masses in an inelastic collision

An ideal spring is attached to a wall, and the other end is attached to a mass $m$. The spring is initially compressed a distance $x$. After it is released, the mass collides with another mass $2m$ ...
-1
votes
1answer
34 views

Decelerating car [closed]

A car crashes into a immovable barrier at 60mph. (a)If the front-end of the car crumples a distance of 1.5 m in the collision, what is the deceleration experienced by the occupants? (Express your ...
3
votes
1answer
50 views

Relationship of multiple particles under collision [closed]

Consider 3 particles. All 3 particles travel along the x-axis. The 1st particle possesses some mass, m, and its initial position is somewhere on the negative x-axis. It has some (positive) velocity ...
0
votes
0answers
14 views

Relationship of multiple particles under collision [closed]

Consider 3 particles. All 3 particles travel along the x-axis. The 1st particle possesses some mass, m, and its initial position is somewhere on the negative x-axis. It contains some (positive) ...
3
votes
1answer
61 views

Why do safety helmets have a softer inner layer nearer the head?

I know that when an object collides onto the helmet, it causes an inelastic collision so that energy is absorbed by the structure of the helmet, so what exactly does the softer inner layer do? Does it ...
0
votes
2answers
74 views

Calculating velocity change after impact?

Let's say there is no gravity here and objects won't crush. We have 2 rocks with $m=10\text{ kg}$. First rock has velocity $v_1=0\text{ m/s}$ and second $v_2=10\text{ m/s}$ (flying in leftward ...
0
votes
2answers
86 views

Ballistic Pendulum Demo Problem

I have a question about the following problem: I got the solution $v=\frac{M+m}{m} \sqrt{2gh}$. But my real question is in the following picture: In the above slide, how can you derive ...
2
votes
3answers
104 views

Elastic collision of point particle and rod

A 1 meter long rod on the ice with mass $m_2=1$ kg is perpendicularly hit on one end by a point particle with mass $m_1=0.1$ kg. The collision is elastic and the point particle is bounced back in ...
-1
votes
1answer
46 views

Initial velocities of a collision [closed]

This is the question: A car of mass 900 kg and a van of mass 1300 kg collide at a crossroads. Investigation into the collision discloses that the car was travelling south east and that the van was ...
2
votes
2answers
137 views

What is the relative speed of two near-light speed particles headed towards each other?

I understand that nothing can move faster than light due to time dilation. I want to build upon my understanding of Einstein's theory of Special Relativity, so I came up with this hypothetical problem ...
1
vote
2answers
115 views

Bullet entering target [duplicate]

I've been given this question: A bullet entering a target with an initial velocity of $ u $ loses $\frac {u}{n}$ of its velocity after penetrating a distance $ a $ into the target; how much ...
0
votes
1answer
138 views

Bullet hits block. Show that linear momentum is not conserved [closed]

"..." First, we will familiarize us with a collision between a homogeneous beam of length, $L$, mass $M$ attached with a frictionless hinge in point $O$ at one of the endpoints of the beam. The ...
2
votes
0answers
106 views

Kinematics and Motion [closed]

If a body loses half of its velocity on penetrating 3cm in a wooden block, then how much will it penetrate more before coming to rest? How does answer come out to be 1cm?
8
votes
3answers
826 views

Number of planks required to stop the bullet [closed]

A bullet looses (1/n)th of its velocity passing through one plank. The number of such planks that are required to stop the bullet can be? Logically, to me the answer seems to be infinity, as always a ...
15
votes
3answers
709 views

What happens in a car crash?

My mom and I were in a car accident. We are ok, but I want to know how fast the car that hit us was going. We were stopped at a light. The car that hit us from behind was a big GMC SUV. Our car was a ...
1
vote
1answer
217 views

What are the general solutions to a hard sphere collision?

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 ...
0
votes
2answers
87 views

Collision of two balls of finite radius [duplicate]

This is your typical elastic collision problem except the balls have finite radius. To be clear: two billiard balls in the plane each with radius $\sigma$ move at constant velocities $v_1, v_2$ ...
-1
votes
1answer
50 views

A block falling from a height on a block suspended by spring [closed]

The block suspended by the spring is hanging freely and its mass is M. The small block of mass m is dropped on the bigger block from height h. After the small block is dropped 》》》 I want help in ...
1
vote
0answers
73 views

2d pool collision with rotational motion

I'm trying to calculate two 2d disks' collision with rotational motion. The collision is perfectly elastic: the sum of translational and rotational energy is conserved. In the instant of the collision ...
0
votes
1answer
86 views

Relative Velocities and Conservation of Kinetic Energy

An object of mass m moves with velocity $v$ towards a stationary object of same mass. Impact is an elastic collision. $v_1$ is the velocity after impact of the mass originally moving $v_2$ is the ...
-5
votes
1answer
84 views

Ascertain the height an object has fallen from given force exerted and mass [closed]

An object of a given mass falls from an unknown height. If the force exerted by the object on contact with the ground is known, how would you ascertain the height from which the object fell?
1
vote
1answer
70 views

How to apply conservation of angular momentum with a shock? [closed]

I got this tricky question, need help. A uniform rod of mass $M$ and length $L$ is attached to an axis at its top, a bullet with mass $m$ traveling at speed $U$ (horizontal) hits the rod at $2L/3$ ...
1
vote
1answer
92 views

Angular Velocity after a frictional impulse

I am modelling 2D physics collision into simulations. In Physics for Game Programmers, Grant Palmer book, the velocity Vn1 after collision is mentioned to be independent of the friction coeff. ...
0
votes
1answer
212 views

How can I calculate the time until collision?

I'm programming a 1 dimensional physics simulator in python. How do I calculate the amount of time until two particle points that are traveling towards eachother collide? I am using the equation: ...
1
vote
1answer
170 views

Electron and photon collision

So electron moving left ($v_{initial}=0.8c$) collides into photon going right. After the collision electron is moving to right ($v_{after}=0.6c$) and the photon is moving to left. What is the ...
1
vote
3answers
736 views

When is energy conserved in a collision and not momentum?

Consider the following example: A bullet of mass 45g is fired at a speed of 220 m/s into a 5.0 kg sandbag hanging from a string from the ceiling. The sandbag absorbs the bullet and begins to ...
0
votes
1answer
62 views

How to calculate the force in an “impulse based reaction model”? [duplicate]

I have a sphere moving forward with v (pre collision) = v1i A second sphere colliding with the first one has its own pre collision ...
2
votes
2answers
218 views

How to calculate velocities after collision?

I'm currently writing a program for a particle simulator. One of the requirements is that the particles collide in a realistic way. However, I don't know how to calculate the final velocities. For ...
1
vote
1answer
158 views

Velocity after inelastic collision between bullet and block [closed]

The following is the problem that I am working on. A bullet of $.01\: \mathrm{kg}$ is shot into a block of mass $.89\: \mathrm{kg}$ that is hanging from the ceiling. After the bullet has been ...
1
vote
1answer
104 views

Confused about elasticity and collisions

I was solving the following problem and the explanation to it confused me. There are two objects with mass $m$ and $M$, respectively. The object with mass $m$ has a velocity of $\sqrt{2gl}$ and ...
5
votes
0answers
206 views

Hamiltonian function for classical hard-sphere elastic collision

I'm trying to find the Hamiltonian function for a system consisting of a single particle in one dimension colliding elastically with a wall at x = 0. Everything I've read on the topic (e.g. this ...
0
votes
1answer
148 views

Antimatter collision - Energy Released

I think it's about time for me to ask this question, as I've been contemplating this for a while. $$E = mc^2.$$ This is Einstein's most famous equation. But what does it mean? On my own, I had to ...
1
vote
1answer
42 views

Decrease in Intensity [closed]

A beam of particles pass through a target made of thin foil of a very small thickness $\Delta x$ having $N$ particles per unit volume. Let the collision cross section be $\sigma$ . If the intensity of ...
1
vote
0answers
31 views

Trouble evaluating an integral arising from particle collision

Assume we have two charged particles colliding. He have particle 1 with mass $m_1$, charge $Z_1 \cdot e$ which travels in $x$-Direction passing by a STATIONARY particle 2 (mass $m_2$, charge $Z_2 ...
0
votes
1answer
154 views

Elastic collision of photon [closed]

Consider an elastic collision of a photon with 100 eV energy hitting a mirror. How much momentum is exchanged in the collision? Also, can one model the reflection of an elastically colliding photon ...
0
votes
1answer
75 views

Direct collision on smooth surface

Hello I have a problem on my hands an I cannot figure out the answer. Two spheres of equal mass on on a smooth surface. sphere 1 is moving at $2v \ m/s$. Sphere 2 is stationary and 1m from a ...
0
votes
3answers
288 views

Collision of two balls [duplicate]

Two balls, with masses $m_1$ and $m_2$ are falling from the heigh $h$. All the collisions are perfectly elastic. Do not consider the size of the balls. $m_1 < m_2$ and lighter ball is on the top. ...
0
votes
1answer
93 views

Question about Cars: Momentum

Car B rests at the bottom of a frictionless inclined plane. In order to travel a height of 0.6m and maintain a speed of 2 m/s at the end of the track it needs to start with 4 m/s. a) If ...
0
votes
3answers
279 views

Which parameter determines how much the 'recoil' or force applied by an object hurts?

Another question from my textbook, directly following after this question: 2 identical bullets are fired, on from a lighter rifle and one from a heavier one, with the same amount of force. Which ...
-3
votes
1answer
160 views

2 particles collision - deriving the equation for an energy which can become mass of new particles!

Q1: Lets say a particle with mass $m_1$ and kinetic energy $W_k$ colides with a particle of mass $m_2$ at rest. Can anyone explain why do both particless ($m_1$ and $m_2$) plus an aditionall mass $m$ ...
0
votes
0answers
377 views

Collision of 2 particles - calculating the mass and a speed after the collision

Lets say we have a particle of mass $m_1$ which has a kinetic energy $W_{k1}$. This particle collides with another same particle. How can i calculate mass $m_2$ and the speed $v_2$ of the particle ...
-1
votes
2answers
521 views

Two balls falling one above the other [closed]

Two balls, first with the mass $m_1$ and the second with the mass $m_2$ are falling from the heigh $h$. Suppose all the collisions are perfectly elastic and do not consider the size of the balls. $m_1 ...
0
votes
1answer
507 views

Bouncing ball simulation computer science

In my Computer science class I was given a problem where I have to simulate a bouncing ball using "real physics". I have been trying to find a equation that will simulate the height of the bounce ...
0
votes
1answer
58 views

Something about collision [closed]

A sphere P of mass m, travelling with speed $u$, makes a head-on collision with a stationary sphere Q also of mass m. After the collision, the velocities of P and Q are $v_1$ and $v_2$ ...