Coefficient of Restitution for a 2-dimensional physics simulator

In summary, the speaker is working on a 2-dimensional physics simulator that includes gravity, electric force, and collisions between spherical objects with varying properties. They are seeking advice on how to improve the collision algorithm and how to handle coefficients of restitution, which currently can only be set globally for all collisions. The speaker is wondering if there is a formula or relation between coefficients of restitution for different objects and if there are other variables that affect the coefficient. They are considering storing a table of representative coefficients for each object, as some materials have well-defined and regulated coefficients. However, for others, the coefficient will need to be measured or estimated. The speaker provides a resource for further information.
  • #1
Nash
7
0
I'm developing a 2-dimensional physics simulator (it includes gravity, electric force, and collisions as of now, between spherical objects of varying masses, charges, and radii). I'm trying to improve my collision algorithm, though, and I'm not sure how to handle coefficients of restitution; currently the program allows a user to choose a global coefficient of restitution that is applied to all collisions, but in reality it varies with materials. However, it is impractical to require the user to select a coefficient between every group of two materials; I need to give the objects some sort of number representing their material, and then using that, their velocities, their masses, their temperatures, or whatever I need to use, determine a coefficient of restitution for each collision.

How ought I to go about this? Is there some sort of formula relation a coefficient of restitution between two objects to their respective coefficients of restitution in collision with a third? Is there some formula relating the coefficient of restitution to other constants and to the properties of an object--or, at least, do you know what variables the coefficient is proportional to?

Thanks.
 
Physics news on Phys.org
  • #2
Store a table giving a representative coefficient for each object you are considering. The COR's for certain objects--baseballs, bats, golf balls and clubs--are well defined and tightly regulated. The insurance industry tabulates COR for different automobiles in collisions at modest speeds. Many materials, like steel, and concrete pavement, are characterized. I don't know of any a priori way to estimate it for others, you'll need to measure it or guess.
 
  • #3

What is the coefficient of restitution?

The coefficient of restitution (COR) is a measure of the elasticity of a collision between two objects. It is defined as the ratio of the relative velocity of separation after a collision to the relative velocity of approach before the collision.

How is the coefficient of restitution calculated?

The coefficient of restitution can be calculated by dividing the relative velocity of separation by the relative velocity of approach. The relative velocity of approach can be calculated by subtracting the velocity of the first object from the velocity of the second object, while the relative velocity of separation can be calculated by subtracting the final velocity of the first object from the final velocity of the second object.

What factors affect the coefficient of restitution?

The coefficient of restitution can be affected by a variety of factors, including the materials and surface properties of the colliding objects, the angle and speed of the collision, and the presence of external forces such as friction or air resistance.

What is a realistic range for the coefficient of restitution?

The coefficient of restitution can range from 0 to 1, where 0 represents a completely inelastic collision (no bounce) and 1 represents a perfectly elastic collision (full bounce). In most real-world scenarios, the coefficient of restitution falls between these two extremes.

How is the coefficient of restitution used in a 2-dimensional physics simulator?

In a 2-dimensional physics simulator, the coefficient of restitution is used to determine the behavior of objects after a collision. It is typically incorporated into the equations of motion to calculate the final velocities of the objects involved in the collision. This allows for realistic and accurate simulations of real-world physics scenarios.

Similar threads

  • Classical Physics
Replies
2
Views
994
  • Classical Physics
Replies
1
Views
1K
  • Classical Physics
Replies
2
Views
3K
Replies
1
Views
1K
Replies
5
Views
3K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Other Physics Topics
Replies
5
Views
106K
  • Classical Physics
Replies
7
Views
721
Replies
1
Views
2K
Back
Top