Collision Definition and 1000 Threads

  1. P

    Why is the answer C never possible for the collision of two vehicles?

    Attempt: I know that the conservation of momentum and energy also applies. Solution: Correct answer is C. But I can't understand how any of the two conservation laws lead to the answer C. The exam report to this question did not even mention anything about this - so, I guess it should be...
  2. xWaldorf

    How is it that momentum is being preserved in a non elastic collision?

    How is it that momentum is being preserved in a non elastic collision? for example let's say that two balls are colliding head-on, not elastically and heat is produced, does that not reduce the momentum of the system?
  3. domingoleung

    How to Calculate Bullet Velocity After Penetrating a Block

    Change in KE = Change in thermal energy 0.5 * (6)* vblock^2 = 0.4 * 6 * 9.81* 0.1 vblock = 0.885 By Conservation of Momentum, (0.05)(854) = (0.05)*vbu + (6)(0.885)I am not sure whether Change in KE = Change in thermal energy is true coz there should be a change in internal energy of the block...
  4. R

    I Relationship between Pileup and inelastic collision events

    I've read some stuff on pileup.In one paper, it says the number of inelastic event approximately equals pileup event in detector.I don't quitely understand it.Can someone explain?Thanks
  5. Frigus

    How momentum is conserved in an inelastic collision

    In inelastic collision their is loss of energy and according to my current knowledge energy can be transferred by either work out heat...Now The problem is that we use law of conservation of momentum in problems related with inelastic and if energy is transferred from our system (two masses)...
  6. Saptarshi Sarkar

    Transition from Elastic to Inelastic collision

    I know that if the collision was not elastic, some of the kinetic energy of the incident neutron wound be used up in some other process. But, I can't understand how I can figure out exactly how much. Even if I can calculate it, I don't know how to find the condition for the collision to go from...
  7. R

    Collision between a block and a curved up-ramp surface

    I tried to solve this question using conservation of momentum. The momentum of the system is mc(vc)=mcvc'+mbvf'. But after that I have no idea I want to use the conservation of kinetic energy but the question doesn't say it's elastic collision, I need to find the velocity of the mb after the...
  8. DuckAmuck

    How Do Inelastic Collisions Distribute Energy Between Heat and Sound?

    In collisions that are inelastic or partially elastic, how can we predict how much of the energy lost to the surroundings becomes heat, and how much becomes sound? What determines that fraction?
  9. P

    Electron and positron collision producing a b0 meson pair

    Conservation of Energy: 9GeV + E = 5.3GeV + 5.3GeV Therefore E = 1.6GeV for the threshold energy. How would I find the velocity of B0 mesons so that I can calculate their mean distance? Then it would just be distance = velocity of b0 * mean proper lifetime Right?
  10. FireAP

    Point sized particle collision and no transfer of energy

    Two identical point-sized particles with the same Y-coordinate were traveling along the X and Z axes respectively. Given that gravity is acting parallel to the Y-axis, will the particles when they eventually collide, continue traveling along the same linear path due to work done by either being 0?
  11. H

    Necessary KE of particles to create a resulting particle in a collision

    So I am making the assumption that the resulting particle Z is emitted at rest. For part a I believe that since the two positron beams are symmetric they would each provide half of the energy to create the Z particle so the KE of each positron would be 91.187GeV/2, I am ignoring the rest energy...
  12. S

    Conservation of Momentum: Elastic Collision of Two Masses

    I really want to know which answer is correct. I don’t really know if I should include velocities to the left as negative velocities in the equation. Is it -1 or 4.33? Please help! Thanks!
  13. isabelle3

    A bullet hits a rod attached to a pivot at one of its ends....

    My initial thought was to use the conservation of energy law since there're no external forces acting on the system bullet + rod. The rod is in rest, the bullet is moving. Then after the collision, the bullet and the rod are rotating around the pivot together, so the kinetic energy of the bullet...
  14. pixel

    One dimensional elastic collision

    A simple model often used to explain solar system gravitational slingshots is to consider a mass moving to the right with initial velocity v1i and a much larger mass moving to the left with initial velocity v2i. After the collision, the first mass is moving to the left with velocity v1f and the...
  15. C

    How to make m1 the subject of the formula

    Homework Statement: an object has a total mass of 75kg and is stationary, it then ejects as a smaller object to the left with a velocity of(+ve direction)7 ms-1(v2) with a mass of m2 , the original object then recoils backwards to the right (-ve direction) at a velocity of -2 ms-1 and a mass of...
  16. LilRubyKinz

    Solving for Missing Values in 1D Collision w/v2 ≠ 0

    My teacher wants me to know how to solve for missing values in a 1D collision when v2 does NOT equal 0. Could someone do me a huge favour and make me a practice question to solve for a missing value when v2 does not equal 0? Or even point one out to me online? And then let me try it out and...
  17. A

    Kinematics and angular speed of a collision between a rod and puck

    initial total KE= (1/2)(0.6kg)(8m/s)^2 = 19.2J (0.6kg)(8m/s) = (0.6kg+1.8kg)(vf) vf= 2m/s final KE= (1/2)(0.6kg+1.8kg)(2m/s)^2 = 4.8J I tried to use linear speed=angular speed * radius : thus 2m/s= angular speed * (3.3m/2) angular speed= 1.2 rad/s Apparently that is wrong.
  18. hnnhcmmngs

    Calculating Collision Frequency of Electrons in Copper Cube

    Homework Statement: Verify the claim of Section 7.2 that the electrons of a metal collide with the surface at a rate of about 10^30 per second per square centimeter. Do this by estimating the collision frequency of electrons in a 1.00-cm cube of copper metal with one face of the cube surface...
  19. hmorenom111

    Finding the equation for final velocity in a perfectly elastic collision

    So after not being able to solve this problem I did some researching online. I was looking around and came across this video, where they give the following equations for solving for the final velocities of both balls: v1f=((m1-m2)/(m1+m2))*v1i v2f=(2m1/(m1+m2))*v1i I plugged in my numbers and...
  20. A

    Collision of a puck and a brick

    x(before) y(before) x(after) y(after) puck (0.36)(13.8)=4.968 0 (0.36)(10.41)cos(α) (0.36)(10.41)sin(α) brick 0 0 (1.35)(1.34)cos(β) -(1.35)(1.34)sin(β) total 4.968 N*s 0 4.968 N*s 0 thus: (0.36)(10.41)sin(α) =(1.35)(1.34)sin(β) β= sin^(-1)[3.747sin(α)/1.809]= sin^(-1)[2.071sin(α)]...
  21. W

    I Matter-Antimatter black hole collision

    From what I understand, a black hole can exist that was formed entirely from antimatter. If this antimatter black hole were to collide or merge with a black hole that has the exact same mass, but was made of regular matter, what would happen? Obviously the matter and antimatter would...
  22. John Justice

    Asteriod collision 65 million years ago in the Mexican Gulf

    At the time of asteroid impact 65 million years ago wiping out the dinosaurs and 50 % of all life on Earth - presuming all but the smallest mammals or sea creatures suggests that humans most likely wouldn't be here today if not for that event because the tiny mammals which then existed would not...
  23. M

    Elastic or inelastic collision?

    If the initial kinetic energy is equal to the final kinetic energy where two objects that collide stick together, this collision is elastic or inelastic?
  24. A

    What slows an object during collision, force or loss of energy?

    I have an example from my machinery handbook which shows the kinetic energy of a pile driver and shows it will drive a pile some distance at a force until the energy is expended. The formula is (Average force of blow times distance)= Weight of object (driver) times distance it falls) Just...
  25. D

    How Should We Prepare for Potential Asteroid Collisions?

    I recently heard in the news that the small asteroid Apophis will be so close to Earth it will be within the Earth's satellite orbits. This asteroid will likely not hit earth, even if it did it wouldn't have an extinction level impact. But there will come a day when we will have to face off with...
  26. naji0044

    Inelastic collision problem: Bullet striking a wood block

    Hey everyone I'm struggling on the last part of this assignment. I need to find the total work done by the block and the bullet, when the collision happens. The informations is: mblock=0.3 kg mbullet=0.01 kg vg=700 m/s Height=0.72m The final speed after the collision is vf=22.6 m/s and the...
  27. Borek

    Estimating Pitch & Volume of Collision Sounds

    I need to develop some kind of simplified formula that will allow me to estimate pitch and volume of a sound of two colliding objects in a simulation. It doesn't have to be exact, mostly it is enough that it follows the intuition - large object produce lower sounds, large and fast object produce...
  28. A

    Elastic Collision: how do the forces and work done make sense?

    Okay, say we have two balls(equal mass and size), 1 and 2. #1 has kinetic energy and #2 is at a standstill, they collide. Ignore all friction, heat, sound losses etc.. Now I know that 1 exerts a force on 2, hence doing work, which in turn uses its kinetic energy up. Therefore, 2 speeds up...
  29. T

    Calculate the *Acceleration* after a (mostly) elastic collision?

    How can I calculate the ACCELERATION of a stationary steel ball after being hit by a moving steel ball. I know how to get the final velocity but how long does it take to accelerate to that velocity from zero? Does it depend on the elasticity of the materials? I guess we need to know long did...
  30. Astroiaco

    I Relationship between collision and relaxation

    Can someone explain me (even in poor worda) the relationship between collision and relaxation? I mean, a structure is relaxed when the particles (or stars) inside have frequent collisions? Or not?An elliptical galaxy is a relaxed structure. Can i deacribe the internal stars with a...
  31. O

    What is the final speed of a mass collision?

    I am stuck, please help. I did the conservation part but then i can't move on.
  32. greenrichy

    Reasons for a gain of momentum during a collision

    I've come up with the following causes: - air resistance - parallax - during the collision, some of the kinetic energy gets converted into thermal energy. - invisible deformations But I'm not sure which would be the biggest effect on the total momentum change. Are there any other reasons that...
  33. Amitayas Banerjee

    What is the angle between the velocity of and the normal to the racket?

    My approach: Let us take two orthogonal axes: x, parallel to the racket's plane and y, perpendicular to it. For the ball to not spin, the components of initial velocities of the racket and the ball along x-axis must be same. Also, as the line of collision is along the normal to the racket's...
  34. M

    Velocity of COM after collision

    I calculated that the velocity of the head prior to the collision is sqrt(2gh), as all of the gravitational potential energy is converted to kinetic energy. And I believe the velocity at point A after the collision is given by the formula vf=e•sqrt(2gh), with e representing the coefficient of...
  35. R

    Acceleration of two Objects after Collision

    This seems like a fairly simple problem but I got the same answer for both so I'm unsure if I am doing it right. I found the accelerations as such a1 = (fk)/(ma) = (98/20) = 4.9 m/s2 a2 = (fk)/(ma) = (73.5/15) = 4.9 m/s2 Am I doing something wrong or is this problem just that simple?
  36. NP04

    Angular Momentum in an Inelastic Collision

    I was wondering why in the video the moment of inertia for the clay ball (upon collision) was simply 1ml^2. That is the constant for a hollow cylinder. The problem specifies that the object is a ball, so the cylinder classification makes no sense, and also I'm pretty sure clay is rather dense...
  37. Lone Wolf

    Two-dimensional perfectly inelastic collision between two vehicles

    a) Let m be the vehicle's mass, M the truck's mass, vt the truck's speed, vc the car's speed, vf the final speed, θ the angle both vehicles make with the horizontal axis (west-east direction) after the collision. Conservation of linear momentum: In the x direction: M vt = (m + M) vf cos(θ) In...
  38. A

    I How does the collision between two atoms work?

    Considering the quantum mechanical model for an atom, what exactly happens when two atoms (say, two Ca2+ ions in a Brownian motion) collide with each other? As I know, this collision is not like a regular elastic or inelastic collision between two macroscopic objects. Is it mainly due to the...
  39. SueJ

    How do I show that 2 moving objects collide?

    They collide when their positions are the same, so I plugged the information for the boat into equation 1 to get an expression for d which is (2i, +j)t^2 Then I used equation 4 to get an expression for d for the branch, which is (-4i, +j)t I would need to take into account the different...
  40. T

    How can we find the missing equation for solving spatial collisions of bodies?

    Good Morning May I ask about spatial collisions of bodies? In undergraduate dynamics, we study that when two particles college, we have two final unknowns: the final velocity of each particle. We first use the conservation of linear momentum. However, we supplement the analysis with the...
  41. PhysicS FAN

    Understanding Force and Momentum in Angular Elastic Collisions

    The speed of the sphere after the impact will be the same since the collision is elastic and the kinetic energy remains the same. So the change of momentum will be given by the cosine law right? What bothers me is the second question about the force that acts on the sphere (which can be given by...
  42. aturcotte16

    How Do Restitution Coefficients Affect Billiard Ball Trajectories?

    The problem I have here is that I can't see how the restitution coefficients (e) will change the trajectory of the ball since the speed of the ball B will be on the same direction as the normal component. And without information one the ball A, I can't see how to resolve that. I will really...
  43. chwala

    How to explain collision theory?

    What activities can one use in explaining collision theory to secondary level students?
  44. AncientOne99

    Average force and angle, collision problem

    Homework Statement [/B] Ball with a mass of 0.1 kg travels at a speed of 10 m /s to the boy. Boy kicks the ball with foot so that it bounces back at an angle of 30 degrees with respect to the horizontal floor. The ball falls back to the ground 20 meters from the boy. With what average force...
  45. K

    Minimum energy positron electron collision producing Z-boson

    Homework Statement Homework Equations m2 = E2 - p2 ([/B]The Attempt at a Solution I got stuck by not knowing how to handle the frames and I thought you can view the Z boson (CoM) frame, but then you simply get that mz = 2me
  46. S

    Determining position of an object after inelastic collision

    Homework Statement A 39,000 lb truck A and a 3968 lb sports car B collide at an intersection. At the moment of the collision, the truck and the sports car are traveling with speeds vA = 70 mph and vB = 30 mph. Assume that the entire intersection forms a horizontal surface. Letting the line of...
  47. K

    4 momentum mass non-conservation, special relativity

    Homework Statement A particle with mass M and speed v along the positive x-axis hits a stationary mass m. Two particles, each with mass µ, emerge from the collision, at angles with respect to the x-axis. (a) Write the equation for conservation of the 4-momenta, for arbitrary angles θ_1, θ_2 of...
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