Collision Definition and 1000 Threads

  1. J

    Finding recoil velocity of an object during a collision

    Hello. I recently began this problem, but the site I'm working this problem on isn't showing me whether the answer is correct or not. Can someone please check my work and just verify that it's correct or state if it isn't and why? 1. Homework Statement A cosmic-ray photon (with mass m...
  2. R

    Mechanics of a car turning left

    Imagine a carom shot in a perfect world. A ball travels diagonally from the lower left-hand corner towards the right cushion and bounces off to head towards the upper left-hand corner. The ball has X and Y momentum. On the collision, the cushion absorbs and then return all the -X momentum to...
  3. velvetmist

    Real life elastic collision and variation of kinetic energy

    How small should ##\Delta T## be in a collision to be considered elastic? In elastic collisions ##\Delta T =0##, but as far as I know, just atomic collisions are considered perfectly elastic. Then, which criterias are used to considere a collision between two objects elastic?
  4. Callista

    Why doesn't Newtons third law also apply to the frame?

    Homework Statement A locomotive has broken through the wall of a train station. During the collision, what can be said about the force exerted by the locomotive on the wall? a)The force exerted by the locomotive on the wall was less than the force exerted by the wall on the locomotive. b) The...
  5. PORFIRIO I

    Electrons colliding with gas molecules

    My concern is an electron tube. From what I understood so far, gas molecules will have an average velocity derived from the Maxwell distribution, and that velocity will influence in the electron collision frequency. I can't see clearly though how the electron velocity itself in the presence...
  6. M

    I Is a "collision" of galaxies noticeable on a planetary scale

    If, as suspected, the Andromeda galaxy "colides" with our own sometime in the far future, would the gravitational forces from passing stars have effect on our solar system? In accelerated models the interaction looks quite violent, but how would it be in our "uncharted backwaters of the...
  7. newrd

    B Andromeda Collision VS Expansion

    Hi Folks, I've read that by the time mankind is ready for intergalactic travel, our nearest galactic neighbour will be too far to even travel to. But I've also read that Andromeda is on a collision course with the Milky Way. Which is correct? And if the universe is expanding and everything is...
  8. S

    Correct statement about perfectly elastic collision

    Homework Statement In perfectly elastic collision between two atoms, it is always true to say that a. the initial speed of one atom will be the same as the final speed of the other atom b. the relative speed of approach between two atoms equals their relative speed of separation c. the total...
  9. kolleamm

    Collision avoidance for moving robotic limbs

    Let's say you have a low force hobby robotic arm that's supposed to perform a certain movement, but it should stop if there is an object in the way. What sort of sensors/solutions exist for this? I've considered force sensors but I'm not sure if that's the best idea since I'd have to place many...
  10. W

    Train collision (linear kinematics)

    Homework Statement A passenger train is traveling at 29ms^-1 and a freight train is traveling 360m ahead of it at 6ms^-1 in the same direction on the same track. The driver of the passenger train has a reaction time of 0.4s before he starts decelerating. What is the minimum deceleration to...
  11. StarWarsNerd

    Collisions Between Two Bodies Undergoing Multiple Transformations

    I have been searching for an answer to this for a really long time and I have not found any definitive answers as of yet. What I am trying to do is determine if and when two bodies collided between the times t0 and t1. Calculating this is much more straight forward if each body is only either...
  12. J

    Collision problem: Two hockey pucks collide and stick together....

    Homework Statement Two hockey pucks collide in a 90 degree angle and stick to each other. What's the speed of the hockey pucks after the collision and in what angle are the pucks moving in. Homework Equations m1=0.71kg m2=0.52kg v1=1.6m/s v2=3.8m/s The Attempt at a Solution m1v1+m2v2=v(m1+m2)...
  13. opus

    Train collision prevention problem

    Homework Statement When a train traveling at 161 km/h rounds a bend, the engineer sees that a locomotive has entered onto the track from the side and is a distance D=676m ahead. The locomotive is moving at 29 km/h. The engineer of the high speed train immediately applies the brakes. What must...
  14. T

    Planetary collision that formed the Moon made life possible on Earth

    https://phys.org/news/2019-01-planetary-collision-moon-life-earth.html The claim is that was how the excess Carbon, Nitrogen, and Sulfur arrived in the Earths crust, without them being in the core. For instance the Carbon/Nitrogen ratio of 40/1 is twice the 'expected' value.
  15. T

    Objects approaching one another with uniform acceleration

    Homework Statement persons 1 & 2 are initially at rest (vi=0m/s) 48m (d) apart. they then run towards each other at constant accelerations person 1 acceleration = 0.50m/s2 person 2 acceleration = 0.30m/s2 how long until they reach each other/collide (t)? at the instant they collide, how far...
  16. B

    Calculate the change in mechanical energy during collision

    Homework Statement A 15 kg block is attached to a very light horizontal spring of force constant 5000.0 N/m and is resting on a frictionless table. It is struck by a 3.00 kg stone at 8.00 m/s to the right, then rebounds at 2.00 m/s to the left. Homework Equations ΔE = ΔK + ΔU The Attempt at...
  17. D

    Three Car Collision - Can physics help clarify twin impact?

    Hi all, need some help... I was involved in a 3 car accident, mine was the middle car. The car in front came to a hard stop and I was forced to a sudden stop. I believe I came to a complete stop very close to the 1st car. Immediately after, the 3rd car behind hit with great force shunting my car...
  18. T

    Maximizing Transferred Energy between n bodies in linear collisions

    Homework Statement My problem has two parts. 1) We have two point masses ##m,M##. and there is another mass ##m_1## between them.They are all aligned in a line. Mass ##M## is moving with speed ##u_1## toward ##m_1## and after collision and all other masses are not moving. we want to find...
  19. Glenstr

    B Another Andromeda-Milky Way "collision" question

    For this exercise let's forget about our suns eventual demise and assume our solar system is intact during the collision/merging. What are the chances of our solar system being adversely affected by the collision? Are the cosmos within the galaxies so vast the chances are infinitesimal, or...
  20. M

    Collision finding final velocity

    1. A baseball of mass 0.30kg is pitched at 70m/s (fwd) at a batter. The ball knocks the stationary 1.7kg ball out of the batters hands and the ball rebounds at 48m/s (backwards). What is the final velocity of the bat as it leaves the batters hand? variables m1 = 0.30 vi= 70 vf = -48 m2= 1.7...
  21. Y

    Finding the mean net force during a collision

    Homework Statement Homework Equations F=ma=mv/t[/B] The Attempt at a Solution I used the equation F=mv/t, in which I find the change in velocity and change in time before and after the collision. The change in time is t2-t1, but the problem comes when I am calculating the change in...
  22. 1

    How to Calculate Energy Produced from Collision of Particles?

    Homework Statement A particle of mass m1 and momentum p1 collides with a particle of mass m2 at rest. A reaction occurs from which two particles of masses m3 and m4 leave the collision along the angles θ3 and θ4 respectively, measured from the original direction of particle 1. Find the energy Q...
  23. Mmarzipan

    Collision with a ball spinning about its vertical axis

    Homework Statement A ball A is rotating on a table with an angular velocity ω about its vertical axis. An identical ball B collides with the ball A elastically. After collision the ball A starts sliding over the table. The coefficient of friction is µ. Find: 1) the angle α between the angular...
  24. J

    Minimum deceleration to prevent a collision

    Homework Statement At a given time ##t=0##, a car 1 moving with constant velocity ##v_{1}## breaks with constant deceleration ##d##. Another car 2 at a distance ##L## behind car 1 and traveling with constant acceleration ##a_{2}## and velocity ##v_{2}## at ##t=0## brakes immediately as soon as...
  25. Sasho Andonov

    I Collision of Milky Way and Andromeda....?

    I do not understand how (in few bilion years) Milky Way and Andromeda will collide? If the universe is expanding and these objects which are far away have bigger speeds than those who are closer, than Milky Way and Andromeda will just be far away every moment... (?) Could someone help? :-)
  26. P

    I Head-on collision of an electron and a proton

    Hey! Let's say we have an electron and proton colliding head-on. We will have ##|p| \sim E## Where ##p_1=(E_1, \vec{p_1})## &##p_2=(E_2, \vec{p_2})## If we want the available energy. We can calculate ##\sqrt{s} = \sqrt{(p_1 + p_2)^2}## We get $$s= p_1^2 + p_2^2 + 2p_1p_2 = m_e^2 + m_p^2 +...
  27. Daniel Wilson

    Is my solution to this question about a collision valid?

    QUESTION Ball A is moving with velocity of v, it collides elastically with five stationary balls. All six balls are of equal mass. What happens next? SOLUTION I want to find out how many balls move off from those that were stationary and with what velocity they move away. I apply the elastic...
  28. jim mcnamara

    NASA NASA asteroid collision warning?

    Yup. Newspapers have it. Again. Note the example "news" article with a very tiny disclaimer. Here are wikipedia's take, some NASA information, and a news article. They are all links and therefore are transient and could change. https://en.wikipedia.org/wiki/2018_LF16...
  29. P

    Speed of a disc after a collision

    Homework Statement I understand that if the change in impulse is 0.25, that because disc B is originally stationary the momentum disc B will have is equal to the impulse. My question is how do we do this in terms of change in momentum? Homework Equations ΔP = Pf - Pi P = mv The Attempt at a...
  30. P

    Final velocities of two objects in a 2D elastic collision

    Homework Statement An atomic nucleous of mass m traveling with speed v collides elastically with a target particle of mass 3.0m (initially at rest) and is scattered at 45o (a). What are the final speeds of the two particles? Advice: eliminate the target particle's recoil angle by manipulating...
  31. E

    Initial velocity in an inelastic collision

    Homework Statement A drunken driver crashes his car into a parked car that has its brakes set. The two cars move off together (perfectly inelastic collision) for 6.0 m. If the mass of the moving car is 1030 kg and the mass of the parked car is 1410 kg how fast was the first car traveling when...
  32. Temple1998

    How do I solve for an elastic collision going up a ramp?

    Homework Statement : Two blocks with masses m1=3kg and m2=4.5kg are moving on a platform with velocities v1 and v2, respectively. The platform is inclined with θ=30ο and is frictionless. Mass m2 has a very stiff spring with constant k=3000kg/s2 attached as shown in the figure. The two blocks...
  33. D

    Finding two objects velocity after an elastic collision

    Homework Statement A 4-kg block moving at 7m/s makes a head-on collision with a stationary block of mass 3kg. Find the velocities of the two blocks after the collision. m1=4kg, vi1=7m/s m2=3kg, vi2 = 0m/s Trying to find vf1 and vf2 2. Homework Equations Using the conservation of momentum...
  34. maxd23

    A Nuclear Reaction: Determining the velocity of neutrons

    Homework Statement Fission, the process that supplies energy in nuclear power plants, occurs when a heavy nucleus is split into two medium-sized nuclei. One such reaction occurs when a neutron colliding with a 235U (uranium) nucleus splits that nucleus into a 141Ba (barium) nucleus and a 92Kr...
  35. Robin04

    Collision of a charged and an uncharged particle

    A charged and an uncharged particle collide. What will be their charges after the collision? The average of the total charge?
  36. M

    Elastic collision with particles, find the kinetic energy

    Homework Statement A proton strikes a stationary alpha particle (4He nucleus) head-on. Assuming the collision is completely elastic, what fraction of the proton’s kinetic energy is transferred to the alpha particle? Homework Equations Pi = Pf Ki = Kf The Attempt at a Solution Tried finding...
  37. Krushnaraj Pandya

    Inelastic collision of ball and rod - rotation problem

    Homework Statement A uniform rod of mass M and length l is hinged at the center. a particle of mass m and speed u sticks after hitting the end of the rod. find the angular velocity of the rod just after collision Homework Equations Energy conservation-0.5mu^2=0.5(m+M)v^2 Angular momentum...
  38. barryj

    Inelastic Collision: Finding Initial Angle

    Homework Statement [/B] After a completely inelastic collision between two objects of equal mass, each having an initial speed of v, the two move off together with a speed of v/3. What is the angle between their initial directions.Homework Equations Conservation of momentum in both x and y...
  39. K

    Relative velocity and force relationship

    This is something related to my job. There are two components A & B both traveling the same direction but at a different velocity. I can find out the exact velocity of both the components when they just hit each other, thus relative velocity is known. Is there a way I find out the force...
  40. J

    Angular momentum after a collision

    Homework Statement A disk of radius ##r## and mass ##m## rolls down an inclined plan. It reaches the end of the plane with velocity ##v_{f}## and collides with a vertical rod of length ##L## and mass ##M## sticking with it. See figure. What is the angular momentum magnitude and direction...
  41. J

    Angular momentum conservation in collision with a nail

    Homework Statement A ball of mass ##m## is attached to a massless string of length ##L##. The ball is released from rest as shown in the figure and as it reaches the bottom of the circle, the string wraps around a nail which is a distance ##d## below the center of the circle. What is the...
  42. A

    Can there be collision-less acceleration of electrons?

    In electron cyclotron resonance of metals/solids can there be electron acceleration without them engaging in collision ? I read the last para of electron cyclotron resonance wikipedia page which stated this
  43. F

    Momentum and collision related problem

    25.0-kg dog is trapped on a rock in the middle of a narrow river. A 66.0-kg rescuer has assembled a swing with negligible mass that she will use to swing down and catch the trapped dog at the bottom of her swing, and then continue swinging to the other side of the river. The ledge that the...
  44. M

    Two decelerating trains on a collision course

    Homework Statement A red and a green train are headed towards each other on a collision course. Red train velocity = 20m/s Green train velocity = 40m/s When the trains are a distance of 950 meters apart, they begin to decelerate at a steady pace of 1m/s^2. 1) Will the trains collide? 2) If...
  45. M

    Elastic collision in one of the particles' frame

    Homework Statement A particle B is standing still while another one, A, is moving towards it with initial 4-momentum ##(E,p,0,0)##. Calculate the change in particle A's 4-momentum as viewed from the particle B's rest frame, in terms of the initial energy E and the scattering angle ##\theta##...
  46. A

    B Black Holes Collide at 0.999c - What Happens?

    The relative speed of two supermassive black holes moving directly towards each other is 0.999 c. What happens when the two black holes collide directly (so the black holes aren't orbiting each other) at such high velocity? Where does all that energy go and how would it effect space time/what...
  47. Spinnor

    B Galactic Collision Creates a Ring of Black Holes and Neutron Stars....

    From, https://www.syfy.com/syfywire/wham-bullseye-galactic-collision-creates-a-ring-of-black-holes-and-neutron-stars ..."“So you have a nice, normal spiral galaxy, right, just out there doing its thing, when BAM! A smaller galaxy careens right through the middle of it like a bullet! Chaos...
  48. M

    Angular speed calculation after an inelastic collision

    Homework Statement A disk [m=0.1 Kg; R=0.1 m] rotates about its center of mass [w=40 rad/s], on a smooth floor. A bar [m=0.1 Kg; lenght=R=0.1 m] moves on the floor with a speed Vb=4 m/s. At one point, the bar hits disk's edge in an inelastic collision, and they start rotating together. A)[Fixed...
  49. G

    Super Basic Collision Problem - Preparation for SR

    Homework Statement [This problem is part of a preparation for modifying the concepts involved in special relativity.] Two cars collide and lock together. They are each a mass of 800 kg and were traveling at a steady 20 m/s in opposite directions prior to collision. a) What's the kinetic...
  50. BeyondBelief96

    What Angle Causes Particles A and B to Collide?

    Homework Statement A particle A moves along the line y = d (30 m) with a constant velocity (v= 3.0 m/s) directed parallel to the positive x-axis (Fig. 4-40). A second particle B starts at the origin with zero speed and constant acceleration (a = 0.40 m/s2) at the same instant that particle A...
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