Physics of a Particle Collision

In summary, an elastic collision between two point masses, m0 and mp, with initial velocities V0i and Vpi, respectively, can be used to calculate the final velocities, V0f and Vpf. However, it is not possible to calculate the initial forces, Foi and Fpi, without additional information such as the time interval of the collision or the position-vs-time data. In an idealized elastic collision, the force is a delta function, representing a very large force acting over a very short period of time. Without details of the collision, the best that can be calculated is a time-averaged force based on the impulse and interaction time.
  • #1
Philosophaie
462
0
I have two point masses, m0 and mp, colliding (with no radii) in an Elastic Collision (no mass loss). One has initial velocity, V0i. The other has initial velocity, Vpi. How do I calculate the initial forces, Foi and Fpi then formulate the final forces, F0f and Fpf yielding the final velocities, V0f and Vpf.
 
Physics news on Phys.org
  • #3
What other information do you nee to calculate Forces? Delta T?
 
  • #4
Philosophaie said:
What other information do you nee to calculate Forces? Delta T?
Yes, but knowing it is elastic, and using the formulas from the link, you can find the velocities after the collision.

Remember that momentum and velocity are vectors. Note that energy is not a vector; it uses the magnitude of the velocity vector.
 
  • #5
What would the equations be for the Forces from the given initial and final velocities?
 
  • #6
For your situation, you should be able to use $$Force = \frac {dv} {dt},$$
So if you know the change in velocity, and the time it took to make that change, then you can find the force.
 
  • #7
@Philosohaie, are you familiar with Dirac delta functions.

In an idealized elastic collision, as a functions of time, velocities are step functions, and the derivative of a step function is a delta function. Hence, the idealized force is a delta function in an idealized elastic collision.
 
  • Like
Likes scottdave
  • #8
In case you don't know (or for anybody else reading this), the delta function is a very large force acted over a very small time. Think of something like hitting a nail with a hammer. In an ideal situation, it would be approaching infinite force happening in a time, approaching zero.
 
  • #9
I think Force is F= dp/dt. For an Elastic Collision each momentum change from initial to final happens over a small time delta T. What I want to know is what the initial and final forces due to their velocities are so they can be summed to zero at the point of Collision.
 
  • #10
For an impact collision [no interaction until contact], the initial and final forces are zero.
During contact, there is a nonzero variation of force-vs-time.
https://www.vernier.com/innovate/impulse-comparison-for-elastic-and-inelastic-collisions/

Have a look at the last force-vs-time graph for a collision on
http://stokes.byu.edu/teaching_resources/forcesensors.html (the graphs are equal because of Newton's Third Law and how the sensors are oriented)

Without details of how the collision occurs [e.g. position-vs-time data from https://serc.carleton.edu/dmvideos/videos/ball_re-bound.html ],
you can't get the details of how the force varies during the collision.
The best you can do is get a "time-averaged force" if you know the impulse and the interaction-time
http://hyperphysics.phy-astr.gsu.edu/hbase/impulse.html

 
  • Like
Likes scottdave

FAQ: Physics of a Particle Collision

What is a particle collision?

A particle collision is when two or more subatomic particles interact with each other, resulting in a transfer of energy and potential creation of new particles.

What is the significance of studying particle collisions?

Studying particle collisions allows us to understand the fundamental laws of nature and the structure of matter. It also helps us to develop new technologies and make advancements in fields such as medicine and energy.

How are particle collisions studied?

Particle collisions are studied using large, complex machines called particle accelerators. These machines accelerate subatomic particles to nearly the speed of light and then collide them in a controlled environment.

What is the role of physics in understanding particle collisions?

Physics plays a crucial role in understanding particle collisions as it provides the theoretical framework and mathematical models to explain and predict the behavior of particles during collisions.

What are some real-life applications of studying particle collisions?

Studying particle collisions has led to advancements in medical imaging technologies, such as PET scanners, and has also contributed to the development of nuclear energy. It has also played a crucial role in uncovering the origins of the universe through experiments like the Large Hadron Collider.

Similar threads

Replies
14
Views
2K
Replies
6
Views
2K
Replies
8
Views
2K
Replies
9
Views
1K
Replies
3
Views
1K
Back
Top