Force on the car in a collision

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SUMMARY

The forum discussion centers on calculating the force experienced by car B during a collision with car A, both having a mass of 1000 kg and accelerating towards each other at 1 m/s². The initial calculation indicates that each car exerts a force of 1000 N, leading to confusion regarding the total force during the collision. The conclusion drawn is that the total collision force on car B is 2000 N, considering the forces from both cars. However, the discussion emphasizes the need for clarity on the nature of forces involved, the timing of the collision, and the concept of momentum rather than merely applying Newton's third law.

PREREQUISITES
  • Understanding of Newton's laws of motion, particularly Newton's third law.
  • Basic knowledge of force, mass, and acceleration (F = ma).
  • Familiarity with the concepts of momentum and impulse in physics.
  • Ability to differentiate between instantaneous force and average force during a collision.
NEXT STEPS
  • Study the principles of momentum conservation in collisions.
  • Learn about impulse and its relationship to force and time (I = F∆t).
  • Explore the differences between elastic and inelastic collisions.
  • Investigate how to calculate average force during a collision using real-world examples.
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding the dynamics of collisions and the application of Newton's laws in real-world scenarios.

  • #31
Nile Anderson said:
how do we define a force again, I think my error lies there , is it not the change of momentum rather than the momentum
It's neither.
A force is something one body exerts on another. A consequence of a force acting over a period of time can be a change in momentum.
Nile Anderson said:
I am thinking really on a resultant
Sure, but you have to identify the body acted on. If you fix on one of the cars, the other car exerts a force on it during the impact, but it does not exert a force on itself, so the resultant is not zero.
To get a zero resultant here you need to introduce a third object for both cars to act on.
 
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  • #32
haruspex said:
It's neither.
A force is something one body exerts on another. A consequence of a force acting over a period of time can be a change in momentum.

Sure, but you have to identify the body acted on. If you fix on one of the cars, the other car exerts a force on it during the impact, but it does not exert a force on itself, so the resultant is not zero.
To get a zero resultant here you need to introduce a third object for both cars to act on.
Newton's Second Law ?
 
  • #33
Nile Anderson said:
Newton's Second Law ?
Applied here how, exactly?
 
  • #34
F=mv-mu/t=m(v-u)/t=ma
 
  • #35
Nile Anderson said:
F=mv-mu/t=m(v-u)/t=ma
I asked exactly how you are applying it in the present context. Which body has mass m? What force acting on the body is represented by F? What time period does t stand for?
Anyway, F=m(v-u)/t is not quite right. That will give you the average force over the time interval t. Likewise, your a is the average acceleration.,
 
  • #36
I see , interpretation then
 
  • #37
Nile Anderson said:
I see , interpretation then
No, not interpretation, application. It doesn't mean anything to quote a law in relation to a problem if you cannot state how the entities in the law relate to those in the problem.
 
  • #38
haruspex said:
No, not interpretation, application. It doesn't mean anything to quote a law in relation to a problem if you cannot state how the entities in the law relate to those in the problem.
I say interpretation to say that you are completely right my friend , I have thought about it and that is what I meant you are right , I started with in inaccurate point, trying to defend that point , but deduction can truly get you know where with an incorrect base
 
  • #39
Nile Anderson said:
I say interpretation to say that you are completely right my friend , I have thought about it and that is what I meant you are right , I started with in inaccurate point, trying to defend that point , but deduction can truly get you know where with an incorrect base
OK.
 
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