# Issac Physics 'Three Collisions' High School Homework - Kinematic

In summary: In the first collision A transfers some momentum to B, so B starts to move. A then moves on with less momentum. In the second collision B transfers some momentum to C, so C starts to move. B moves on with less momentum. In the third collision C transfers some momentum back to B, so B starts to move again, this time in the opposite direction. C moves on with less momentum. In the fourth collision B transfers some momentum back to A, so A starts to move again, also in the opposite direction. B moves on with less momentum. In the fifth collision A transfers some momentum back to B, so B starts to move again in the original direction. A moves on
Homework Statement
Three particles A, B, and C, each of mass π, lie at rest in that order in a straight line on a smooth horizontal table. The particle A is then projected directly towards B with speed π’.

The masses of A, B, and C are now π, 2π and 3π respectively:

Again find the fraction of π’ that C moves with immediately after the second impact, assuming the collisions are perfectly elastic. Give your answer as a decimal to three significant figures.
Relevant Equations
Kinetic energy: πΎ=0.5ππ£^2
Momentum: π=ππ£
Homework Statement: Three particles A, B, and C, each of mass π, lie at rest in that order in a straight line on a smooth horizontal table. The particle A is then projected directly towards B with speed π’.

The masses of A, B, and C are now π, 2π and 3π respectively:

Again find the fraction of π’ that C moves with immediately after the second impact, assuming the collisions are perfectly elastic. Give your answer as a decimal to three significant figures.
Homework Equations: Kinetic energy: πΎ=0.5ππ£^2
Momentum: π=ππ£

Increase in mass = increase in momentum, but not sure if that means an increase in momentum transferred.

3?

I know this may be too easy for advanced physics, but I need urgent help! Thank you!

The link to the question: https://isaacphysics.org/questions/three_collisions_num?board=a48e1e5b-c230-44b8-85c5-d38076cb543f

Three particles A, B, and C, each of mass π, ...
and
The masses of A, B, and C are now π, 2π and 3π respectively:
as if the collisions make the masses go different. But apparently the first quote applies to part a and the second to part b.

How did you solve part a) and why can't you apply the same math to part b) ?

Increase in mass = increase in momentum
There is no increase in mass. These are two separate questions. In part a the masses are equal, in part b they are different.

Homework Statement: Three particles A, B, and C, each of mass π, lie at rest in that order in a straight line on a smooth horizontal table. The particle A is then projected directly towards B with speed π’.

The masses of A, B, and C are now π, 2π and 3π respectively:

Again find the fraction of π’ that C moves with immediately after the second impact, assuming the collisions are perfectly elastic. Give your answer as a decimal to three significant figures.
Homework Equations: Kinetic energy: πΎ=0.5ππ£^2
Momentum: π=ππ£

Increase in mass = increase in momentum, but not sure if that means an increase in momentum transferred.

3?
you have to remember that increased mass means increased inertia which means that it would takje more momentum to move this particle a a certain speed.
if you have 3 particles in a perfectly elastic collision both energy and momentum would be conserved, you should put the equations that say that the momentum before the collision is equal to the momentum after the collision (of the WHOLE system) , and then another equation that states that the kinetic energy before the collision is equal to the kinetic energy after the collision (Of the whole system, by this I mean of the 3 particles)

Fdtroya said:
you have to remember that increased mass means increased inertia which means that it would takje more momentum to move this particle a a certain speed.
if you have 3 particles in a perfectly elastic collision both energy and momentum would be conserved, you should put the equations that say that the momentum before the collision is equal to the momentum after the collision (of the WHOLE system) , and then another equation that states that the kinetic energy before the collision is equal to the kinetic energy after the collision (Of the whole system, by this I mean of the 3 particles)
That whole system approach does not in itself furnish enough equations. Each collision needs to be treated separately.

## 1. What is "Three Collisions" in Issac Physics?

"Three Collisions" is a homework assignment on kinematics in Issac Physics. It involves solving problems that require the application of the laws of motion and the principles of conservation of momentum and energy.

## 2. How difficult is the "Three Collisions" homework in Issac Physics?

The difficulty of the "Three Collisions" homework can vary depending on the level of understanding of the student in kinematics. However, it is generally considered to be a challenging assignment that requires critical thinking and problem-solving skills.

## 3. How can I prepare for the "Three Collisions" homework in Issac Physics?

To prepare for the "Three Collisions" homework, it is important to have a strong understanding of the laws of motion and the principles of conservation of momentum and energy. It is also helpful to practice solving problems similar to those in the homework assignment.

## 4. What are the key concepts covered in the "Three Collisions" homework in Issac Physics?

The "Three Collisions" homework covers key concepts such as velocity, acceleration, momentum, and energy in the context of three-body collisions. It also involves understanding and applying the laws of motion and the principles of conservation of momentum and energy.

## 5. Can I seek help if I am struggling with the "Three Collisions" homework in Issac Physics?

Yes, there are various resources available for students who are struggling with the "Three Collisions" homework in Issac Physics. You can seek help from your teacher, classmates, or online tutorials and forums. It is important to ask for help when needed to gain a better understanding of the concepts and improve your problem-solving skills.

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