# What is 2d collision: Definition and 38 Discussions

Box2D is a free open source 2-dimensional physics simulator engine written in C++ by Erin Catto and published under the MIT license. It has been used in Crayon Physics Deluxe, Limbo, Rolando, Incredibots, Angry Birds, Tiny Wings, Shovel Knight, Transformice, Happy Wheels, and many online Flash games, as well as iPhone, iPad and Android games using the Cocos2d or Moscrif game engine and Corona framework.

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1. ### Potential Energy - 2D inelastic collision - ballistic pendulum

I really can't find anything in my textbook about how PE relates to 2D collisions, but here is what I do know... ΔPE = mgΔh And I know that since it is a completely inelastic equation kinetic energy is not conserved but momentum is conserved. The change in kinetic energy should be equal to the...
2. ### Momentum in a perfectly inelastic collision

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...
3. ### Counter-intuitive 2D collision

Consider a slope with mass, that can move in the horizontal plane without friction. A ball is dropped and hits the slope with restitution coefficient e. How to calculate the final velocities? How can I solve something like this? Note that it's not a simple 2D collision, it has a restriction...
4. ### Inelastic 2D Collision with Vector Components

Homework Statement Two balls with mass m and 4m collide at the location x=y=0 and stick. Their initial velocities just before the collision can be represented as v1=(i+j) v and v2=(j-i)v' respectively. Their final velocity vf makes an angle θ with the +x axis. Find v and v' in terms of vf and...
5. ### Angular-Linear Momentum Collisions

Hi there, A friend of mine is creating a physics engine in java (mostly as a challenge I believe). Today he asked me a question about the results of collisions between objects. For example, imagine that these 2 objects collide: The results of such a collusion would be something like this...
6. ### Solving 2D Momentum Collision: What is the Final Velocity After Collision?

Homework Statement One car of mass 1400 kg is traveling at 45km/h when it collides and becomes entangles with another car mass of mass 1300 kg traveling at 39km/h[E]. What is their velocity after collision So MA = 1400 kg VA = 45kh/h MB = 1300 kg VB = 39 kh/h [E] and After Collision: MAB =...
7. ### Solve 2D Elastic Collision Homework Statement

Homework Statement Problem: An object of mass m1 elastically collides with an object of mass m2 =(3/2) m1 that is initially at rest. The less massive object has speed v1 and travels at an angle of θ1with its original direction (x-axis) after collision; the more massive object has a speed of v2...
8. ### 2D Elastic Collision Using Conservation of Momentum

Homework Statement Two objects collide and bounce off one another. After the collision, object m1 = 2.74 kg moves off at 12.8 m/s at a heading of 295 degrees. Object m2 = 2.28 kg moves off at 12.8 m/s at a heading of 241 degrees. Initially, m2 was traveling at 11.1 m/s at a heading of 334...
9. ### What Are the Final Velocities of Hockey Pucks After a Glancing Collision?

Homework Statement Two equal mass hockey pucks undergo a glancing collision. Puck 1 is initially at rest and is struck by puck 2 traveling at a velocity of 13 m/s[E]. Puck 1 travels at an angle of [E18N] after the collision. Puck 2 travels at an angle of [E4S]. Determine the final velocity...
10. ### Conservation of Momentum 2D Collision angles/directions

Hi, I googled 2d elastic collisions to see if I could find a problem where two objects are approaching each other from different directions before collision and then moving away from each other at different directions after collision, but I noticed that all the problems I've found have 1 of two...
11. ### Maximum angle for 2D collision

Homework Statement A mass m1, with initial velocity u, collides elastically with mass m2, which is initially at rest. After collision, m1 deflects by angle θ. Find the maximum value of θ. The answer given is θmax=acos(sqrt(1-(m1/m2)^2)). Does this mean that the maximum angle cannot exist if...
12. ### Comp Sci 2D collision detection / determining final velocity - Java

Homework Statement Determine if two circular objects (both moving or one stationary), collide and if so, determine their final velocity. The two objects are being rendered using Graphics's Java library class, updating their position 60 times per second. Their position (x,y) is determined based...
13. ### Car-Truck Collision: Initial Common Velocity

Homework Statement A car with a mass of 1400 kg is westbound at 50 km/h. It collides at an intersection with a northbound truck having a mass of 2000 kg and traveling at 40 km/h. What is the initial common velocity of the car and truck immediately after the collision if they have an...
14. ### Finding the Collision Point of Two Objects Using Velocity and Position

I have 2 objects: Obj1 have a Velocity of vel1 and position of (x1, y1) Obj2 have a Velocity of vel2 and position of (x2, y2) Using time = distance / velocity knowing that they will collide.. can I assume distance1 / vel1 = distance2 / vel2 ? distance formula = sqrt((x - x1^2) + (y - y1^2)) Can...
15. ### 2D Collision of 3 Billiard Balls

Homework Statement A 500 g billiard ball is going at 10 m/s [E] when it impacts 2 other identical billiard balls. Afterwards, you observe 2 of the balls moving at 2 m/s [30 W of S] and 3 m/s[45 N of E] respectively. Calculate the Energy lost in the collision. Homework Equations KE = 1/2mv^2...
16. ### Impulse / 2-D Collisions / Need Clarification?

Homework Statement A baseball with a mass of 0.152 kg is moving horizontally at 32.0 m/s [E], when it is struck by a bat for 0.00200 seconds. The velocity of the ball just after the collision is 52.0 m/s [W 20⁰ n]. a) Find the impulse experienced by the ball? b) Find the average net force of...
17. ### 2-D Elastic Collision: finding final velocities

This is a modified problem from the one posted a few days ago. I’ve been unsuccessfully trying to solve it since then, so maybe it’s time to ask for some help. I’ve changed the quantities :) 1. Homework Statement The mass of puck 1 is ##0.2\ kg## and that of puck 2 is ##0.25\ kg##. The...
18. ### 2D Elastic collision of varying mass, velocities, and angles

Problem statement: Two pucks of radius 0.05 meters collide as shown in attached picture. The mass of puck 1 is 0.1 kg and that of puck 2 is 0.15 kg. The initial velocities are v1i = 1 m/s and v2i= 0.6 m/s. (1) Assuming no friction between the pucks, only normal forces during collision, in...
19. ### Finding Final Velocity of Mass 1 After Collision

Homework Statement Mass 1 (2.77 kg) moves with an initial velocity (1i - 1j) and mass 2 (1 kg) starts at rest. After the collision, M2 moves with a velocity of (2i - 3j). What is the final velocity of m1?Homework Equations Since they don't stick together, KE and linear momentum are conserved...
20. ### 2D collision of billiard balls

Homework Statement Two billiard balls of equal mass move at right angles and meet at the origin of an xy coordinate system. Initially ball A is moving along the y axis at +2.0 m/s, and ball B is moving to the right along the x axis with speed +3.7 m/s. After the collision (assumed elastic)...
21. ### Resultant velocities from 2D collision

Homework Statement Suppose you have two 2D circles, where size ≈ mass, each of which is moving with known x- and y-velocities. The two collide, not necessarily head-on (one could broadside the other, etc). How do I calculate the resultant velocities, assuming no elasticity or friction...
22. ### 2D Collision : Glancing Collision

Homework Statement Two balls of equal mass m undergo a collision, the velocities of the balls make angles of 25.5° and -45.9° relative to the original direction of motion of the moving ball. (a) Draw and label a diagram to show the balls before and after the collision. Label the angles...
23. ### Elastic 2D Collision with Lots of Unknowns

Homework Statement Mass m1, moving to the right, collides with mass m2, which is at rest before the collision. The masses are m1 = 0.1 kg and m2 = 0.2 kg. The scattering angle of m1 will be 30 degrees above the horizontal. a) Calculate the recoil angle phi of m_2. b) Calculate the recoil...
24. ### How to find the unknown mass of an object in a 2d collision?

Homework Statement I have two pucks colliding. PUck 1 has a mass of .545 kg. Puck two has the same puck mass, but also has a weight added onto it. I need to find the mass of puck two. Velocity before and after for puck 1: V1i = 2.0m/s[19°Below the Horizontal] V1f = 3.0m/s[31°Above the...
25. ### 2D collision, both angles given, both final velocities unknown.

I'm trying to figure out what formula to get started in this question: A 7kg bowling ball moving with a velocity of 8 m/s strikes a single pin of mass 1.36kg. The impact deflects the bowling ball 10 degrees from it's original path. The pin moves along a path 45 degrees from the original path...
26. ### 2D collision response with friction

I'm writing a little 2D physics engine. The collision response is calculated by working out the impulse (and so, change in momentum) on each object, and takes into account the objects' velocities, angular velocities, and the fact that the collision normal may be in a different direction to the...
27. ### Finding Coefficient of Restitution for 2D Collision

Linear momentum 2d collision Homework Statement Two particles A and B of mass m and 3m respectively, A collides with B. Find the coefficient of restitution e if \textbf{v}_{A} is purely in the \textbf{j}-direction. Velocity of each particle before collision. \dot{\textbf{r}}_{A}=9...
28. ### 2D Collision b/w two objects, How do I find the speed of the centre of mass?

Hi, I was attempting to work through this question. Anyways, I was working from a graph, so the radius 2.5 cm, the two of them collided, it was an inelastic collision as the two objects did part ways, so how do I find the centre of gravity? I attempted to calculate it... but if someone could...
29. ### Why is the collision angle 90 degrees in a 2d collision?

Homework Statement Stationary ball is placed 20 degrees to the right of the moving ball's trajectory. Both balls are of same weight. Collision occurs and balls part at 90 degree angle. We measured it and it was 90 degrees on two occasions. Explain why it is 90. Homework Equations...
30. ### Simple 2D collision formula developments

Hi everybody, I am currently working on a small computer programming project, and was wondering if you could give me hand. Say I have two simple, identical balls moving in different speeds and angles towards each other. They hit each other elastically, and weigh exactly the same. The...
31. ### How to Solve 2D Collision Billiard Balls

Homework Statement Two billiard balls of equal mass move at right angles and meet at the origin of an xy coordinate system. Initially ball A is moving upward along the y-axis at 2.0, and ball B is moving to the right along the x-axis with speed 3.7$m/s$. After the collision (assumed...
32. ### Solving 2D Collision: Find v1 &amp; v2 Magnitudes

A fireworks rocket is moving at a speed of 45.0 m/s. The rocket suddenly breaks into 2 pieces of equal mass, which fly off with velocities v1 and v2. v1 creates an angle of 30 degrees above the x-axis and v2 creates an angle of 60 degrees below the x-axis. What is the magnitude of v1 and v2?
33. ### Exploring 2D Collision Physics with Polygons: Analysis and Simulation

I am trying to analyze the physics of a 2d collision among polygons. I supplied you with an image that illustrates my attempt: http://s278.photobucket.com/albums/kk112/beloxx/?action=view&current=collision.jpg"...
34. ### Solving the 2D Collision Between Particles of Same Mass

Homework Statement Ok, I'm making an algorithm to calculate some stuff, and meanwhile, i needed to compute a 2D collision between 2 particles of same mass. To work that out, I needed to change referential to Mcenter. The problem was there... Homework Equations Vcm=(v1+v2)/2 (m1=m2)...
35. ### Is this 2D collision elastic or inelastic? Calculate to find out.

A rocket of mass M = 30kg is traveling with velocity V = 1500m/s horizontally. When it explodes into two chunks of mass m1 = 20kg and m2 = 10kg. The mass observed to be moving at an angle of (theta1) 20 above the horizontal with a speed of 1000m/s just after the explosion. Find the magnitude and...
36. ### Solving 2D Collision Problem with Equal Masses and Elastic Collision

Ok, I have tried to work this out for about an hour now and I haven't gotten very far. In the question there are two equal masses. One of them is moving at a given velocity and the other is not moving at all. After the collision one disk goes off on a given angle while the other disk goes off on...
37. ### Velocities of balls after 2D collision

If a ball at 5m/s struck two stationary balls and it is repelled back at -3m/s at an angle of 15 degrees, what would be the velocity of ball #2 if ball #1 traveled at 1m/s and 10 degrees from the normal?
38. ### Predicting Outcome of 2D Collision w/ Initial Quantities

In my text, it says that the conservation laws alone do not suffice to predict the motions of two particles if the collision occurs in two dimensions. It is generally required that we know one of the final quantities in order to predict the rest. Does this mean that it is impossible to predict...