What is Collision: Definition and 1000 Discussions
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word collision refers to incidents in which two or more objects collide with great force, the scientific use of the term implies nothing about the magnitude of the force.
Some examples of physical interactions that scientists would consider collisions are the following:
When an insect lands on a plant's leaf, its legs are said to collide with the leaf.
When a cat strides across a lawn, each contact that its paws make with the ground is considered a collision, as well as each brush of its fur against a blade of grass.
When a boxer throws a punch, their fist is said to collide with the opponent's body.
When an astronomical object merges with a black hole, they are considered to collide.Some colloquial uses of the word collision are the following:
A traffic collision involves at least one automobile.
A mid-air collision occurs between airplanes.
A ship collision accurately involves at least two moving maritime vessels hitting each other; the related term, allision, describes when a moving ship strikes a stationary object (often, but not always, another ship).
In physics, collisions can be classified by the change in the total kinetic energy of the system before and after the collision:
If most or all of the total kinetic energy is lost (dissipated as heat, sound, etc. or absorbed by the objects themselves), the collision is said to be inelastic; such collisions involve objects coming to a full stop. An example of such a collision is a car crash, as cars crumple inward when crashing, rather than bouncing off of each other. This is by design, for the safety of the occupants and bystanders should a crash occur - the frame of the car absorbs the energy of the crash instead.
If most of the kinetic energy is conserved (i.e. the objects continue moving afterwards), the collision is said to be elastic. An example of this is a baseball bat hitting a baseball - the kinetic energy of the bat is transferred to the ball, greatly increasing the ball's velocity. The sound of the bat hitting the ball represents the loss of energy.
And if all of the total kinetic energy is conserved (i.e. no energy is released as sound, heat, etc.), the collision is said to be perfectly elastic. Such a system is an idealization and cannot occur in reality, due to the second law of thermodynamics.
I just started studying Quantum physics and i'm learning about Comptonspreading and I have this question in my book that I don't completely understand
So if an electron is standing still, then it gets hit by a photon moving in a straight line into the electron. The photon then bounces off the...
I know that the speed of the centre of mass is ##v_{cm}=(mv_0+mv_0)/(2m)=v_0##.
But I don't know how to proceed from here with the angular speed around the centre of mass of the system.
Any help will be appreciated.
I tried to calculate it, but I think I'm going wrong way.
I found m^2/s^2 in the definite integral...
(170539114.487m^2/s^2)
I don't know what it means!!
I am stuck with this problem.
Intuition tells me the answer is no, but I am struggling to prove it.
If we consider two particles travelling in the same direction, the 2nd particle will gain velocity (impulse is in same direction to velocity), and the first particle will lose velocity (if it...
The collision seems to be an inelastic collision meaning momentum is conserved however, energy is not due to likely thermal energy from the collision. Using conservation of momentum, we can maybe somehow find the initial momentum of each vehicle and set it equal to the final momentums? However...
A previous question I got correct was: During this time interval, what is the y-component of the average net force on her? It was just 2625, and I thought question 2 would be the same answer but it wasn't. Not sure what to do.
I draw a series of images of the problem situation. In (a), the first ball in green is (just) dropped at time ##t=0##. In (b), the second ball in red is dropped at time ##t=2\;\text{s}##. In (c), the first ball rebounds after a total time of falling down ##t_d##. At this position, its velocity...
Hi,
I assumed I was supposed to find the amount of kinetic energy body 2 receives after contact, assuming the collision is central, body 1 will be at rest after the collision.
I started by using the equation for conservation of momentum:
\begin{align}
m_1v_1 = m_1v_1' + m_2v_2' \\
50 * 20 =...
an assumption being that since the M ( that is mass is a constant for the vehicle ) and a being the same as if the vehicle were to have been crashed into a stationary obstacle, that F would be the same as if said vehicle were to have been crashed into a stationary obstacle and not another...
What happens generally when a neutrino/anti-neutrino collides with a light vs heavy atom?
My guess is, since neutrinos have very low cross section, their interaction is weak and therefore it will be an elastic scattering! For example:
$$ \overline{\nu} + He^3 \rightarrow \overline{\nu} + He^3...
Imagine there is a square plate fixed at the edge on all sides, it is impacted by a body with a pre-determined kinetic energy. Now assume that this plate is submerged in water and impacted by an identical body with the same amount of kinetic energy. Will the results be different? How to...
Before the collision, the total linear momentum of the system is ##p = mv##, where ##m## is the mass of the minor asteroid and ##v## is its velocity. The total angular momentum of the system is ##L = mRv##, where ##R## is the radius of the major asteroid. Since there are no external forces or...
Hello guys,
I need help on this problem,
"You throw a ball with a mass of 0.4kg against a brick wall. It hits the wall moving horizontally to the left at 30 m/s and rebounds horizontally to the right at 20m/s. (a) Find the Impulse of the net force on the ball during its collision with the wall...
For this problem,
The reason why I am not sure whether it is a valid assumption whether momentum is conserved because during the collision if we consider the two masses to be the system, then there will be a uniform gravitational field acting on both masses, and a spring force that is acting...
Hello,
I ask you for your aid in the solution of the following problem. Please see the attached illustration.
Two objects (red and blue) are moving in the vicinity of each other. The red object is moving along a closed circle and the blue object is moving along a line. Our objective is to...
Hi everyone
I'm making a game in which a player's laser can destroy enemies and cancel out enemy lasers. My code for the player laser executes queue_free() when it enters the collisionshape for the enemy laser and enemy. The player laser is only supposed to destroy one item per shot...
Hi everyone
I'd like to detect collisions between a circle and a floor.
I have set them up as follows:
The script runs fine (it's just a circle falling towards the floor), but nothing happens when the two objects collide.
Does anyone know what I've done wrong?Thanks
Hello all:
Watching few news , titanic came and we start to have a question , can I prove that titanic was sunk because of hitting an ice mountain, and not because of torpedo, should we use material specifications , speed of the ship , and material specifications of the ice mountain
or we...
$$ \frac{5E-3*v^2}{2} = (2 + 5E-3)(10)(0.2)(2) $$
v = 56.64
I just don't get how this is the wrong answer....it's just simple conservation of energy, right?
The cylinder in question would have a moment of inertia of ~1.67kg*m² and rotational KE of 2.058J. At the point of impact also, assuming the body hits the sphere at a 90deg angle after traversing 90deg of displacement, it should(?) exert a force of 1.31N - enough to give an acceleration of...
Question:
With maximum do they mean that the speed of the pions is the same as the proton and an antiproton? Otherwise there will be two unknowns, and if I use both relativistic-energy and momentum conservation equations I get difficult equations.
Hi There!
I am quite a beginner at physics and my aim is to apply physics to a computer program which I'm coding.
The program consists of 2 balls of equal mass colliding into each other and demonstrating the trajectories after an elastic collision.
I have already coded a more basic model...
Hi,
Here is the problem
What is required to answer this question is two assumptions. Firstly, the component of the momentum normal to the centre line is the same before and after. Therefore, secondly, A must recoil entirely in the horizontal plane. This is the only way to answer this question...
Diagram : I draw a picture of the problem situation and paste it to the right.
Attempt : Let me assume that the position of the smaller mass ##m## at a given instant of time ##t## is ##x(t)##.
(1) Gravitational potential energy ##\frac{GMm}{x} = \frac{1}{2}mv^2(x)##, where ##v(x)## is the...
When a coin is dropped from a certain height and collides with a glass surface, is the majority of the potential energy converted to sound or heat? And how would one determine this as I only hear the sound and cannot measure the significant change in temperature?
I'm curious about impact on falling object, so i have taken initiative to solve this problem.
I considered only force on the falling object would be its weight and taken F=mg. With only limited data m=.25kg and drop height h=1m.
Pondering on this consideration practically, it will have more...
1) The Hilbert space for each particle and the system are:
##H_1={\ket{\frac{1}{2} \frac{1}{2}}; \ket{\frac{1}{2} -\frac{1}{2}}}##
##H_2={\ket{1 1}; \ket{1 0}; \ket{1 -1}}##
##H=H_1 \otimes H_2##
2) I'm not sure what "considering the total Hamiltonian" means, but I think that the two CSCO...
I found that 1/2m1v1i^2+1/2m2v2i^2=1/2m1v1f^2+1/2m2v2f^2
=>0.5*200*55^2+0.5*46*0^2=0.5*40^2*200+0.5*46*0*vf^2=>vf=78.713 m/s.
The true answer is 65.2 m/s and is solved using m1v1i+mvv2i=m1v1f+m2v2f. Are these equations not interchangeable? Why can I not use the equation I used?
Equation 1 is equating the kinetic energies of the objects before and after the elastic collision. Equation 2 is equating the momentums of the objects after the elastic collision. They can be used interchangeably as long as the collision is elastic.
Am I right in my conclusion?
I calculated:arctan(fy/13.0)=55=>fy=18.566 m/s
Then I calculated, using the momentum equation:
m1viy+m2v2iy=(m1+m2)vfy=>
mv2i=2*m*18.566=>v2=37.132 m/s
I thought that because the cars were stuck together, the kinetic energy from the northbound car would be lost. So, the speed would have...
I have been trying to make sense of the derivation of pressure under Kinetic Theory of Gases chapter, but it's not making sense to me when the impulse momentum equation is used for the collision between a gas molecule and the wall of the container.
The book says that for the elastic collision...
For part(a),
The solution is,
However, I made a mistake somewhere in my working below and I'm not sure what it is. Does anybody please know? Thank you!
Here is a not too scale diagram at the moment of the collision,
## \vec L = \vec r \times \vec p ##
## \vec L = -y_{com}\hat j \times...
For this problem,
Why for part (a) the solution is,
Is the bit circled in red zero because since the putty is released at a very small distance above the rod it velocity is negligible?
Also for part (d) the solution is
I did a computation of the initial and finial kinetic energies of the...
For this part (b) of this problem,
The solution is,
However, would a better explanation be:
As the spheres are conductors, there will be free electrons within and on the surface of the conductors that will be polarized by the external electric field between the conductor. This will decrease...
For this problem,
The solution is,
However, is the reason why they don't include electrical potential energy because the time interval for which we are applying conservation of energy over is very small so the change in electric potential energy is negligible?
Also, when they said, "electrons...
If a neutron star and an anti neutron star collided, would they 1) completely annihilate each other, 2) form a black hole, or 3) partially annihilate each other with the remaining stars being pushed away from each other by the energy created?
Using principle of conservation of momentum:
m×u=m×v1 + M×v2
Where m=mass of moving particle in the beginning
u=Initial velocity of particle m
v1= final velocity of particle m
v2=velocity of object M
m×u-(mv1)=Mv2
(mu-mv1)÷M=v2
My answer is this (mu-mv1)÷M
However, it is nowhere close to...
Greetings everyone.
I learned that the distance between molecules in liquid increases while the temperature increases. Hence, its density is decreased. The process is thermal expansion. At the same time, the collision between molecules would be more frequent when the temperature increases...
I'm a little confused as to what the answer could be. This was one of my homework questions that I got wrong as I chose 0.5 v as the answer. Would someone be able to tell me what the correct answer would be?
Hello, i was wondering, during the pair creation caused by the collision between a very energetic proton and a target (atomic nucleus) in a particle accelerator, what happens to the very energetic proton after the collision? Is it destroyed, intact, split into quarks or something else?
Thank you!
I know I need to look at the conversation of momentum, as well as the conservation of kinetic energy. However I get stuck with my equations. Any help would be greatly appreciated! I've already got (don't know where I am going wrong):
(v)^2 + (1/2)(m)(v)^2 = (vf1)^2 + (1/2)(m)(vf2)^2
(3/2)v^2 =...
Suppose I have two spheres in 3 dimensions of equal mass. In cartesian coordinates, sphere A is traveling with velocity uAi, and sphere B travels with vBi. They will collide elastically.
I want to find the final velocities after the collision, ie uAf and vBf.
Am I correct in saying that...
From conservation of momentum:
m1u1 + m2u2 = m1v1 + m2
u1 - u2 = v1 + v2 (u2 is negative because the object moves to the left)
From conservation of KE, I got answer (C)
So there are two correct answers, (B) and (C)?
Thanks
Hello there, can I get some help with (b) please?
first of all I wanted to ask.. can is it permitted to use different systems in one exercises?
like f.e. for conservation of energy to find the velocity of ##m_3## I used as system only ##m_3## but for the collision I used the 3 masses as the...
Synopsis, The insurance company wants to repair this 3-year-old motorcycle with 3400 miles on the odo father taking this hit. The motorcycle was modified with an aftermarket "engine guard," which was made out of powder-coated steel tubing and bolted directly to the frame which is made out of...