# Question about momentum transfer

In summary: This is an important skill!In summary, momentum is conserved, so if a steel ball moves at 1 meter/sec collides head on with the left side of the array, the ball furthest to the right in the array will begin swinging away from the array 1 second after the first ball collided.
Hi.

I'm trying to figure out how transfer of momentum works so that I can simulate it reasonably accurately and understand it on an intuitive level.

My intuition goes like this:

Momentum must be conserved. Therefore, if for example I had a 1 meter long Newton's Cradle with numerous polished steel balls on it, spanning the whole length, then if a steel ball moving at 1 meter/sec collides head on with the left side of the array then the ball furthest to the right in the array will begin swinging away from the array exactly 1 second after the first ball collided with the left side.

In other words, my intuition is that in momentum space it would be as if the original ball had never collided at all and just continued traveling along the space. Whereas, in contrast, in physical space, this would amount to the momentum being transferred along the line in order to achieve the equivalent effect.

Is my intuition correct?

Is the amount of time momentum transfer requires in the presence of collisions equivalent to the amount of time the original momentum would have taken to traverse the system without the presence of the colliding bodies?

This is all of course assuming that no energy is lost anywhere.

Your intuition is wrong. The momentum transfer occurs much faster than the speed of the balls. If the balls were perfectly elastic I'm guessing that the momentum transfer would happen at the speed of sound in whatever material the balls were made out of.

seeing is believing

Last edited by a moderator:
There are two different mechanisms transferring the momentum here.

Before the impact, the momentum is being carried with the matter in the ball, as it moves. The "velocity of the momentum" is the same as the velocity of the ball, and could be anything.

The other mechanism is transferring momentum through a solid, by the forces acting between the atoms of the material. As #2 said, that always happens at the same speed, which is the speed of sound in the material. The speed of sound in most metals is about 5 times faster than in air.

But don't worry too much about being wrong here. The same sort of confusion can occur elsewhere in physics, for example the apparent speed of waves on the surface of water, compared with the motion of the water itself. The good thing is that you were thinking about what was going on.

Hello,

Your intuition is correct in that momentum is conserved and that it can be transferred through collisions. The example of the Newton's Cradle is a good illustration of this concept. When the first ball collides with the left side, it transfers its momentum to the rest of the balls in the array, causing the ball on the far right to swing away. This is because the total momentum of the system must remain constant.

In terms of time, the amount of time it takes for momentum to transfer through collisions is not necessarily equivalent to the amount of time it would take for the original momentum to traverse the system without collisions. This is because the collisions themselves can affect the speed and direction of the objects involved, potentially slowing down the transfer of momentum. However, in a perfectly elastic collision where no energy is lost, the transfer of momentum would occur in the same amount of time as the original momentum would have taken to traverse the system.

I hope this helps clarify the concept of momentum transfer for you. If you have any further questions, please don't hesitate to ask. Keep up the good work in simulating and understanding this important concept in physics.

## 1. What is momentum transfer?

Momentum transfer is the transfer of momentum from one object to another during a collision or interaction. It is a measure of how much motion is being transferred between two objects.

## 2. How is momentum transfer calculated?

Momentum transfer is calculated using the formula p = m * v, where p is momentum, m is mass, and v is velocity. This formula can be used to calculate the change in momentum for an object before and after a collision.

## 3. What factors affect momentum transfer?

The factors that affect momentum transfer include the mass and velocity of the objects involved in the collision, as well as the angle and duration of the collision. In general, objects with a larger mass and/or higher velocity will have a greater momentum transfer.

## 4. How is momentum transfer important in science?

Momentum transfer is important in many areas of science, including physics, engineering, and chemistry. It helps us understand the behavior of objects in motion and how they interact with each other. It is also essential for designing and optimizing systems and processes, such as in transportation and energy production.

## 5. Can momentum transfer be conserved?

Yes, according to the law of conservation of momentum, the total momentum of a closed system will remain constant before and after a collision. This means that the amount of momentum transferred between objects will be equal and opposite, resulting in a net change of zero in the system's total momentum.

Replies
3
Views
1K
Replies
34
Views
2K
Replies
8
Views
2K
Replies
2
Views
409
Replies
9
Views
2K
Replies
4
Views
2K
Replies
3
Views
1K
Replies
3
Views
1K
Replies
3
Views
1K
Replies
4
Views
1K