What is Collisions: Definition and 706 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.
Homework Statement
A bicycle wheel of mass M (assumed to be concentrated at its rim) and radius R is mounted horizontally so it may turn without friction on a vertical axle. A dart of mass m0 is thrown with velocity v0 as shown above and sticks in the tire. ( A top-view is shown to the right.)...
Perfectly elastic collisions problems usually involve calculating the final velocities of two masses from their initial momenta. Trying to derive such formula I got a different result, a shorter formula to solve the same problem:
Take two masses a and b with their respective initial...
Homework Statement
We are only given variables in this problem, that is:
m1 travels at V, collides with 2m which is at rest
results in m going off at 45° at V1
2m also goes off at 45° down at V2
Calculate V1 and V2 in terms of V
Homework Equations
Ʃρx-initial=Ʃρx-final...
Homework Statement
A 10 g ball going at a speed of 5 m/s is kicked, and flies off at an angle of 35° at 25 m/s. What was the force of kick?
Known:
m = 0.0010 kg
vi = 5 m/s
θ = 35°
vf = 25 m/s
Homework Equations
mvi = mvf
F = ma
The Attempt at a Solution
Would this count as an...
So we had some questions in lab today that left me confused. Someone please tell me what I'm not understanding here?
We start with a light mass moving at velocity v, having linear momentum p=mv and kinetic energy (mv^2)/2, and a heavy mass at rest, with linear momentum p=M(0)= 0 and kinetic...
Homework Statement
A 1 Kg car moving at 2m/s collides elastically with a stationary car. The first car rebounds opposite to the original direction at 1m/s and the second car moves off in the original direction of the first car.
A) What is the mass of the 2nd car
B) What is the speed of...
Two objects of masses 2.0 kg and 6.0kg slide without friction
down the sides of a hemispherical bowl. Both start with zero velocity at
the lip, which is 12 cm above the bottom. The objects collide at the bottom of the bowl. Just
before the collision, they are moving at right angles to each...
Here are 3 problems I have been working on. Any help would be very much appreciated. Thank you in advance!
Homework Statement
Two inelastic balls are traveling toward each other with velocities -4m/s and 7 m/s and they experience an elastic head on collision
a)obtain the velocities...
1. A bumper car with mass m1 = 105 kg is moving to the right with a velocity of v1 = 4 m/s. A second bumper car with mass m2 = 98 kg is moving to the left with a velocity of v2 = -3.8 m/s. The two cars have an elastic collision. Assume the surface is frictionless.
2.Vcm= (m1v1+m2v2)/m1+m2
V1 in...
Homework Statement
A particle of mass m approaches a stationary particle of mass 3m. They bounce off elastically. Assume 1D. Find the final velocities using the center of mass coordinate system.
Homework Equations
(All quantities with r or v are vectors r1 and r2 represent the...
Will some of the stars of the Milky Way crash into those of Andromeda if these galaxies merge?
What are the odds? How large a share of the stars will this happen to?
Thanks
So why is kinetic energy not conserved while momentum is conserved in a perfectly inelastic collision?
Where does the kinetic energy go when the objects collide perfectly inelastically?
Why does conservation of momentum happen? Is momentum a type of energy?
Thank you for your help.
If car 1 has a a mass(m) and car 2 has a mass(2m), in a head on collision, with both cars traveling the same velocity, which car experiences a bigger acceleration ?
my answer - car 1
If two identical cars with identical speeds and masses collide, the impulse received by each car is the...
Homework Statement
Two objects moving in opposite directions with the same speed undergo a totally inelastic collision, and half the initial kinetic energy is lost. Find the ratio of their masses, m1/m2.
Homework Equations
m1v1+m2v2=(m1+m2)vf
The objects are moving in opposite directions...
Homework Statement
A 10.0g bullet is fired into a stationary block of wood (m=5.00 kg). The bullet imbeds into the block. The speed of the bullet-plus-wood combination immediately after the collision is 0.600 m/s. What was the original speed of the bullet?
ball m=10.0g=0.01kg
wood m=...
A stationary object with mass mb is struck head-on by an object with mass ma that is moving initially at speed v0.
If the collision is elastic, what percentage of the original energy does each object have after the collision?
I don't know how to find percentage.
Homework Statement
An unstable nucleus of mass 1.70 10^-26 kg, initially at rest at the origin of a coordinate system, disintegrates into three particles. One particle, having a mass of m1 = 5.40 10^-27 kg moves in the positive y-direction with speed v1 = 7.20 106 m/s. Another particle...
valence Z=1, lattice param a = 4.05 conductivity = 1.76e7 . What's the avg time between collisions of a conduction electron in this metal (bcc structure).really have no idea lol
These may seem like silly questions, but seeing as I'm not a physics major (I teach myself about what interests me in any subject really), I could use some clarification on the issue.
Does an anti-particle annihilate only when it meets its "regular matter" particle counterpart, or will the...
Homework Statement
What fraction of the energy of a rapidly moving proton is not available for inelastic interactions in proton-proton collisions when the target proton is at rest in the laboratory and the energy of the accelerator is (a) 3 GeV (b) 7 GeV (c) 25 GeV (d) 200 GeV (e) 1000 GeV...
This is not dircectly a coursework question, rather I need someone to tell me what is correct and what is not correct in my assumption of Momentum and collisions, esp conservation of linear momentum.
For some reason I stand to believe there are two diffirent equations for conservation of...
Homework Statement
This is an experiment involving colliding 2 gliders on an airtrack. Initial and final speeds are both recorded. I need to plot a graph that proves the Conservation of Momentum holds true, but I can't seem to get the correct Y and X axis variables. Assuming both masses m1 and...
Hi everyone. I believe that I'm in the right place for this topic. If not, please excuse me for the misplacement :)
I am a programmer, not a physicist, so please excuse my lack of knowledge. I currently need help with an energy conservation problem.
I am currently working on this problem...
in a movie stunt, a 65 kg skier starts from a rest postion at the top of a hill 30 m high. she slides down the hill to the bottom, where she collides with a 45 kg stationary skier. the collision is completely inelastic. find the fiinal velocity of the skiers.
ATTEMPT.
i know i have to use...
In an elastic head-on collision, a 0.60 kg cart moving at 5.0 m/s (W) collides with a 0.80 kg cart moving at 2.0m/s (E). the collision is cushioned by a spring (k=1200 N/m)
a find the velocity of each cart after the collision
b find the maximum compression of the spring
ATTEMPT...
Homework Statement
if m1 and m2 (m1= m2, (vm1 = 4m/s)) collide at an angle λ (60°) we can fully predict oucome:
angles (60° and 30°) and speeds (2 and 3.46)
can we predict the outcome if we know that m1/m2 = 3/ 5 ?
First off, i'd like to note that this isn't homework, and I've seen other threads in here that deal with question/equation/problems, so I hope this isn't against the rules. I found this on a practice physics test online. I'm just using it for the benefit of my knowledge, nothing more.
I can...
Homework Statement
Question:A 2,800kg car is traveling at a velocity of 22m/s. The car hits the wall and comes to a complete stop. The collision took 0.3 seconds.
a. What is the cars impulse?
b. What force did the wall exert on the car?
c. What force did the car exert on the wall?
d...
Homework Statement
A 0.045kg Steel marble collides obliquely with an identical stationary marble, and continues at 55 degrees to its original direction. The collision is perfectly elastic. What is the angle between the direction taken of the target (previously static) ball and the original...
Can anybody tell me if any research is currently being carried out,or planned,to investigate further high energy electron/electron collisions?If so what sort of information may such research reveal?The only thing I can think of is that any research may be able to test Coulombs law down to...
Alrighty, I'm working on a three dimensional physics simulator that does every operation in spherical coordinates and vectors, and I'm stuck on figuring out elastic collisions. are elastic collisions essentially trading momentum between the two colliding bodies? I'm assuming not, but i can't...
Hello all. I have what seems to be a fairly simple problem but I need a bit of help on the reasoning and what happens in a qualitative sense if some factors change.
The problem is of e.g. a larger spherical type thing happily traveling along at a fixed velocity but with a smaller (e.g. 10x...
Hi everybody.
That's my first (of many) post here!
I'm a brazilian guy who is trying o solve de Wopho's Problems.
And onde of then called my attention for the criativity using an (theoterically) easy concept of elastic collision.
The problem is the second...
Homework Statement
Two 2.1 kg balls are attached to the ends of a thin rod of negligible mass, 63 cm in length. The rod is free to rotate in a vertical plane about a horizontal axis through its center. With the rod initially horizontal as shown, a 50 gm wad of wet putty drops onto one of the...
Homework Statement
I am trying to write (for my own interest) a program in C that solves a simple 1-dimensional physics problem. I want the program to determine the times (after t=0) of the first ten collisions for two elastic balls constrained between elastic walls at x=0 and x=a.
The user...
I've recently been looking for information on how to describe elastic and inelastic collisions in a way that spans the full set of possibility of different levels of elasticity between objects.
In both of my physics textbooks I was only able to find quantified information on the two extremes...
Hi,
I am wondering if all the old collisions problems from beginning physics can still be applied and solved for using quantum mechanics. For example. In mechanics we used conservation of momentum and kinetic energy in elastic collisions to solve for out-going momentums of pool balls. Can...
Homework Statement
here is a picture of the problems I am having trouble with:
http://oi55.tinypic.com/2llca50.jpg
or if that doesn't work: http://tinypic.com/view.php?pic=2llca50&s=7
Homework Equations
for question 1:
part 1: p1 + p2 = p`1 + p`2 and Distance=Time*Speed
part 2: W(f)...
Homework Statement
Q: Two air track gliders of masses 300g, and 200g move towards each other in opposite directions with speeds of 50cm/s and 100cm/s respectively. Take the direction of the more massive glider as positive.
If the collision is elastic, find the velocity of each glider AFTER...
Homework Statement
A sample of gas (H2) is kept within a container with a piston seal (of mass M) at the top. This piston can move freely. Let's say the pressure on the piston above it is one atmosphere.
If we then put this container in a reservoir of ice then the volume of the gas will...
Hi guys, just wanted to clear a few things up for myself..
By rearranging the conservation of momentum and conservation of energy equations I think I've shown that a collision that involves the colliding objects moving off together after the collision (like a bullet getting stuck in a...
I am sure many of you are familiar with the Impulse-Momentum Theorem:
\Deltap = F * \Deltat
Is there any way to mathematically derive the time that the two objects would stick together during the collision without using the left side of the equation?
Homework Statement
A proton with kinetic energy T1 = 10MeV scatters elastically from a stationary carbon - 12 nucleus. The scattered proton emerges at 30o to its initial direction.
a) Draw a sketch to represent the b4 and after conditions for this collision in the lab reference frame...
What would happen if an electron were accelerated in an attempt to collide with an accelerated proton in a particle accelerator?
What would happen in a collision between an electron and a neutron?
Homework Statement
1. A red car with a velocity of 20mph north collides with a blue car that is stopped at a stoplight. On which car is the force greater?
2. A red car with a velocity of 25mph north collides with a blue car with a velocity of 15 mph north. Which one feels a greater force...
A cart with mass 370 g moving on a frictionless linear air track at an initial speed of 1.7 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. After the collision, the first cart continues in its original direction at 0.42 m/s.
(a) What is the mass of the...
Homework Statement
A ball is dropped straight down onto a wedge that is sitting on top of a frictionless surface. The wedge is at an angle of 45degreees and has a mass of 5.00kg. The ball has a mass of 3.00kg.
If the ball collides with the wedge at 4.50m/s, and the collision is instantaneous...
Hi, I'm trying to make a 2d simulation of elastic colliding balls. I have a hard time deriving the motion equations after collision. For each ball i know the speed, the mass and the angle of movement. Can anyone point me in the right direction to find the general equations for this ? I need the...
Homework Statement
Three carts of masses 4.0 kg, 10 kg, and 3.0 kg move on a frictionless horizontal track with speeds of 5.0 m/s, 3.0 m/s, and -4.0 m/s, as shown in Figure P6.34. The carts stick together after colliding. Does your answer require that all carts collide and stick together at...