Collision Definition and 1000 Threads

  1. P

    How can momentum be conserved in an inelastic collision?

    Say I drop a ball of mass 5kg from a height of 2 meters, assuming no air resistance, it will hit the ground with a velocity of 6.26m/s and collide with the ground, and rebound. From the law of conservation of momentum, 6.26 * 5 = v * 5, where v is the new velocity of the ball. But if the ball...
  2. B3NR4Y

    Solve for mass using a graph of a collision

    Homework Statement A 1-kg standard cart collides with a cart A of unknown inertia. Both carts appear to be rolling with significant wheel friction because their velocities change with time as shown in. What is the mass of cart A? The graph below should be used to solve for the mass...
  3. T

    Collision with a sword placed in the wall at high speeds

    Suppose that I am wearing some super boots that can allow me to travel anywhere from 0 to about 99% of c.Now I use these boots to travel alongside a wall and this wall at some point has a very sharp sword jutting out of it. It is safe to presume that anyone with the sword in his hand can easily...
  4. B

    Calculating Angular Velocity and Energy Dissipation After Collision and Rotation

    Hi there, right now I am making my first steps towards physics, and I would appreciate your help to solve some of my problems. As you surely have already noticed, I'm not english and I guarantee I'll make thousands of errors. Should I make any, please, try to always advise me, and if it's not...
  5. P

    Confusion with train collision with constant acceleration

    The problem statement A train starts out from Stavanger at 8.14, in direction of Kristiansand. It goes with constant speed, 80.0km/h until Sandnes, a distance of 15.0 km. Then it accelerates (instantaneously) to 120 km/h and proceeds towards Kristiansand. Kristiansand is 250 km from...
  6. A

    Why proton and electron collision doesn't result in annihilation?

    I am new to particle physics, but I heard that electron and positron annihilate each other in case of contact mainly because both have opposite charge( even same mass). Consider an electron is given enough kinetic energy such that it compensates mass differentiation between proton and electron...
  7. S

    Answer: Car A Crash Distance: Solving System of Equations

    Homework Statement Car A is traveling at a speed of 31.0 m/s, car B is 3.5 meters behind car A traveling at the same speed. Suddenly, car A comes to a halting stop. Car B's reaction time to the stop is 0.85 seconds. Even if you assume both cars slow at the same rate, a crash will occur. Assume...
  8. F

    Elastic Collision of Blocks on a Half-Pipe: How to Determine the Final Heights?

    Two blocks are released from rest on either side of a frictionless half-pipe. Block B is more massive than block A. The height HB from which block B is released is less than HA, the height from which block A is released. The blocks collide elastically on the flat section. After the...
  9. D

    Collision of ball with a fixed inclined plane

    if a ball of mass m were to strike an fixed incined plane of 45degress with velocity of 3m/s, and was rebounded horizontally, what would be the velocity of the rebounded ball.(elastic collision). this the method i have tried. momentum of the system along the x-axis is conserved.therefore...
  10. A

    Statistical mechanics, bernoulli's forumula - collision freqency

    Hello, I am having trouble understanding collision frequency in following discussion from Kubo, $$collision\ frequency = \frac{1}{\frac{l}{v_{x}}}=\frac{p_{x}}{ml}$$ What am I missing ?
  11. J

    Satellite Collision: Find Max Mass mj for Orbit Without Hitting Earth

    Homework Statement A satellite of mass m is in a circular orbit of radius 2RE around the Earth. The satellite hits a piece of space junk of mass mj. The space junk, which was initially at rest, sticks to the satellite. The satellite and junk then fall as one in a new elliptic orbit around the...
  12. C

    Two different masses in an elastic collision

    Before you go through all the trouble of reading all this back story the real information is towards the bottom starting at KEM1=KEM2=KEt. Hello, i was currently playing with a two separate masses ( a yoga ball, and a small bouncy ball, yes i know juvenile), while i bounced the two objects with...
  13. Nirmal

    Calculate Angular Velocity After Ball-Rod Collision

    Homework Statement To understand the question first see the attachment (picture). The ball hits the rod and then it sticks to the end opposite the pivot. So now what is the angular velocity (ω) just after collision. Homework Equations 1/2m_1v_1^2 + 1/2 I_1ω_1^2 = 1/2mv^2 + 1/2 Iω^2...
  14. T

    Projectile Motion Collision Problem

    Homework Statement A particle P is projected from the origin with initial speed 5 m/s and projection angle theta. At time t = 0, when P is at the origin, another particle Q begins to move on the (horizontal) x-axis with initial speed 15/4 m/s and constant acceleration a = 3g/4 m/s^2...
  15. T

    Collision of Two Swinging Bars, Maximum Angle

    Homework Statement Two uniform bars have masses and lengths of m, l and 2m, 2l, respectively. The bars are pivoted at the common frictionless hinge as shown. The bars are released from the horizontal position in such a way that they collide and stick together at the bottom position. After...
  16. K

    Elastic Collision 4: Final Velocities

    Homework Statement Two identical masses collide. one is at rest. what are their final velocities. Homework Equations The relative velocities before and after the collision are identical: ##v_1-v_2=-(u_1-u_2)## The Attempt at a Solution I draw the final velocities in the same...
  17. gcombina

    A head-on Collision (Example #7) page 205 Cutnell & Jhonson Physics 8e

    One ball has a mass of m1 = 0.250 kg and an initial velocity of 5.00 m/s. The other has a mass of m2=0.800 kg and is initially at rest. No external forces act on the balls. What are the velocities of the balls after the collision? Elastic Collision. On the book I have this formula. STEP 1#...
  18. davidbenari

    Elastic collision against a wall

    In an elastic collision against a wall, where the angle of incidence is equal to the angle of deflection, why is it assumed that friction effected no impulse, and only the normal force did? I can understand if this was stated in the problem by saying "frictionless surface, or whatever" but this...
  19. Greg Bernhardt

    How Do Inelastic Collisions Work?

    Definition/Summary A collision is said to be inelastic if the total kinetic energy of all the bodies involved in the collision changes. So conservation of kinetic energy does not apply. But conservation of momentum, and of angular momentum, does apply to all unrestrained collisions...
  20. Greg Bernhardt

    What is the difference between elastic and inelastic collisions?

    Definition/Summary A collision is said to be elastic if the total kinetic energy of all the bodies involved in the collision remains constant. Most collisions are NOT elastic. Conservation of momentum applies to ALL unrestrained collisions. Equations For a two body collision...
  21. C

    Perfectly elastic collision, both velocities unknown

    Homework Statement Ball 1, with a mass of 110g and traveling at 15m/s , collides head on with ball 2, which has a mass of 350g and is initially at rest. What are the final velocities of each ball if the collision is perfectly elastic? Homework Equations Conservation of momentum: m1u1 +...
  22. J

    Collision -- why there is no parallel component?

    say that a particle collides elastically with a wall 60 degrees from the wall's normal. the force from the wall is along the wall's normal. My questions is why there is no parallel component to the force from the wall since the particles velocity had a parallel component.
  23. T

    Collision of two initially moving objects

    So I know how to solve for two initially moving objects that collide one way, but I was reading on this website another way to do it and I am not understanding a step. I've included a picture of the site and underlined the step I don't understand. I've tried a couple ways but I can't get it...
  24. Nathanael

    Why is this inelastic collision problem solvable?

    This problem comes from the inelastic collision section. Homework Statement "In Fig. 9-63, block 1 (mass 2.0 kg) is moving rightward at 10 m/s and block 2 (mass 5.0 kg) is moving rightward at 3.0 m/s. The surface is frictionless, and a spring with a spring constant of 1120 N/m is fixed to...
  25. P

    Ball collision momentum problem

    Homework Statement Hello. I was solving this problem about two balls in a plane colliding elastically. The first one had mass 100g radius 5cm and started with velocity of 3m/s to the right and hit the second ball with mass 50g radius 3cm(initially stationary). It hit the second ball such...
  26. powerof

    Change in temperature after an inelastic collision

    Homework Statement We have a sphere of mass M=0.75 Kg hung from the ceiling by a massless tense cord. Said sphere is hit by a projectile/bullet of mass m=0.015 Kg with velocity v_{0}=300 m/s and they are stuck together (inelastic collision). Find the height the (projectile+sphere) object...
  27. dean barry

    Two - body collision energy and velocity

    Here is the problem : Two heavenly bodies (m1 and m2) (non orbiting) in free space at a distance D are released from rest and allowed to approach each other under gravitational influence to a final distance d. This is the way I've worked the problem : The total potential energy difference...
  28. Art_Vandelay

    Find the Angle between Due East and the System after the Collision

    Hi, everyone! This is my first post on this website. I answered the first part of the problem correctly, but I have gotten Part B wrong many times (after trying different approaches) and haven't attempted Part C yet. I would really appreciate any and all advice and assistance with this problem...
  29. Rookie

    Elastic Collision in Deep Space

    Hello! I need help with this physics problem, I've some what attempted it and I need some feedback. ANY help would be awesome! Homework Statement Two objects (A and B) of equal mass, undergo an elastic collision in deep space. Initially, B is at rest and A approaches at velocity v. The...
  30. BrainMan

    How to Determine Final Speeds in a Glancing Collision Problem?

    Homework Statement Two identical shuffleboard disks, one orange and the other yellow, are involved in a perfectly elastic glancing collision. The yellow disk is initially at rest and is struck by the orange disk moving with a speed of 4 m/s. After the collision, the orange disk moves along a...
  31. BrainMan

    Calculating Final Speed and Kinetic Energy in an Elastic Collision

    Homework Statement A ball of mass = 3-kg moving to the right at 3 m/s collides elastically with a ball of mass m2 = 2 kg moving at 4 m/s to the left. Find (a) the final speed of each object and (b) the kinetic energy of each ball before and after the collisions. Homework Equations V1i...
  32. Maxo

    Is Gravity Involved in the Motion of a Pendulum After a Collision?

    Homework Statement Homework Equations ∑F=ma The Attempt at a Solution This is a problem that can be solved by looking at impulse and momentum and I understand how the problem is solved in the book but I'm wondering about the reasoning before, if this is the only way to look at it...
  33. BrainMan

    What is the Solution to a Perfectly Inelastic Collision Problem?

    Homework Statement A 90-kg halfback running north with a speed of 9 m/s is tackled by a 120-kg opponent running south with a speed of 3 m/s. If the collision is perfectly inelastic and head-on, calculate. (a) the velocity of the players just after the tackle and (b) the total energy lost as a...
  34. S

    Collision of thermal neutrons and Cobalt

    Homework Statement The cross section of ##^{59}Co## for capturing the thermal neutrons is ##2000 fm^2##. A ##10g##, thin paper of ##^{59}Co## is radiated for ##100 hours## in reactor with neutron flux ##2\cdot 10^{18} /m^2s##. Density of ##^{59}Co## is ##8.9g/cm^3##. Half life time of...
  35. K

    Max Shortening of Spring for Elastic Collision 3

    Homework Statement 2 masses moving on a friction less surface. one of 2 kg moving at a speed of 10 and one of 6 kg moving at the speed of 4. at the back of the heavier one is a spring with a constant k=800. What is the maximum shortening of the spring Homework Equations Conservation of...
  36. C

    MHB How Does a Spring Affect the Outcome of a Ball and Plate Collision?

    The ball (mass m) strikes the heavy steel plate (mass M) with a velocity of v=30m/s at an angle of 60 degrees with the horizontal. the plate is initially stationary. If the coefficient of restitution is e=0.7 and the spring stiffness is k=155N/m. Calculate the final velocity of the ball and the...
  37. K

    Solving Elastic Collision 2 Homework

    Homework Statement I made an example, two masses colliding elastically according to the drawing. i only know the direction of the first mass after collision (can i determine also the velocity?) I try to solve but i go into difficulties. Homework Equations Conservation of momentum...
  38. K

    Validity of Elastic Collision Equations in Two and Three Dimensions

    Homework Statement In a one dimensional elastic collision there are two equations: conservation of momentum and conservation of energy. by solving those 2 sets we get that the relative velocity before equals minus the relative velocity after: v_1-v_2=-(u_1-u_2) Is this equation valid also in...
  39. K

    Elastic Collision Homework: 3kg Mass, 4m/s Velocity, 2kg Resting Mass

    Homework Statement A body of mass 3 kg slides on a friction less surface with velocity 4 m/s and collides elastically with a resting mass of 2 kg. calculate the final velocities. Homework Equations Conservation of momentum: m_1v_1+m_2v_2=m_1u_1+m_2u_2 Conservation of energy...
  40. adjacent

    What causes nuclear fission in a collision between two neutrons?

    What will happen if we collide two neutrons? As far as I know,since they have no charge, there won't be any repulsive forces. So one neutron will go through the other.:eek: Is this true? What about nuclear fission? Why does the neutron split the nucleus when there are no forces present?
  41. L

    Work done on a rigid body in a collision

    Sorry if this question has already been considered in this Forum (I'm sure it is but I can't find it now). A rigid ball slide without friction in an horizontal plane and collide elastically with a wall, the plane of which is perpendicular to the ball's velocity. During the collision the ball...
  42. T

    Odds of Collision between Incident Object and Target Objects

    Homework Statement The problem is what are the odds of an incident object of radius r1 colliding with any of a collection of target objects of radius r2, where the r2 objects have a number density N / m^3 = n and the incident object travels a distance L. Incident object is moving much faster...
  43. S

    Collision question involving velocity, Kinetic energy and conservation

    Homework Statement A 50 gram steel ball moving on a frictionless horizontal surface at 2.0m.s^-1 hits a stationary 20 gram ceramic ball. After the collision the ceramic ball moves off at a velocity of 2.5m.s^-1. (i) Calculate the velocity of the steel ball after the collision. (ii) Calculate...
  44. A

    What is the Resulting Velocity of Ball 3 in a 3-Body Elastic Collision?

    This may be intuitively obvious to you and I'm just missing it. Say you had 3 balls each with a mass of 1g. Each moving at velocity of 10m/s on a 2D Cartesian plane. Ball 1 & 2 are moving toward the origin from opposite sides, so they are approaching each other at 20m/s. Ball 3 moving from...
  45. T

    Inelastic collision of two particles

    Homework Statement After a completely inelastic collision, two particles of the same mass m and same initial speed v are found to move away together with the speed (2/3)v. Find the angle between the initial velocity vectors of the objects. The Attempt at a Solution It is completely...
  46. N

    2 dimensional collision confusion

    Homework Statement A 2 kg mass with initial velocity v = (5i + 7j) collides perfectly elastically with a 3 kg mass with initial velocity v = (-1i -3j) After the collision, the 2kg mass has a speed of √50 m/s and the 3 kg mass is traveling at an angle of 329.77Θ as measured from the...
  47. W

    Relativistic collision of two protons to produce a proton-antiproton

    Homework Statement What is the minimum proton energy needed in an accelerator to produce antiprotons by the reaction: P+P \rightarrow P+P+P+\bar{P} The mass of both protons and antiprotons is m_p. Assume first that the initial protons have equal energy (the lab frame is the...
  48. M

    Good luck, and let me know if you run into any more problems!

    Homework Statement https://scontent-a-sjc.xx.fbcdn.net/hphotos-prn1/t1.0-9/603671_1409914319284787_3441607163537875560_n.jpg Homework Equations conservation of total momentum M1V1+M2V2 = MtotVf The Attempt at a Solution I tried using the COTM as such: x...
  49. B

    Sub atomic collision and modulation

    when two sub atomic particles collide, being waves as well as particles. at point of collision do they act like radio waves and modulate each other. Are the resultant particle/waves produced by collision equivalent to upper and lower sidebands (as in AM modulation) or bessel functions (as in FM...
  50. T

    Maximum Compression of Spring in Block Collision

    Homework Statement A 1.0-kg block slides on a frictionless, horizontal air track with an initial velocity of v = 2.0 m/s. It collides with another 1.0-kg block, which is initially at rest. One end of an ideal massless spring of spring constant k = 200 N/m is attached to the second block, so...
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