Choice of reference frame in conservation of momentum/energy problems

In summary, when solving problems related to conservation of momentum/energy, it is beneficial to use a reference frame that is either stationary to the center of mass or stationary to the ground/observer. In Newtonian mechanics, any inertial reference frame can be used. However, if there are no external forces, using an inertial frame where the center of mass is stationary can simplify the problem, especially in collision problems.
  • #1
sodaboy7
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Problems related to conservation of momentum/energy can be solved by taking reference frame which is stationary to center of mass or which is stationary to ground/observer. So when to use what frame or which frame is beneficial in which case/type of problems? I m confused !:confused:
 
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  • #2
If you are talking about Newtonian mechanics, you can use any inertial reference frame you like.

If there are no external forces acting on the system, the CM moves with constant velocity, so you can use an inertial frame where the CM is stationary. For example in simple collision problems this is very nice, because the velocities of two approaching objects must be +p/m1 and -p/m2 where p is the momentum of one of the objects, and for a collision with a coefficient of restitution e, the velocities after impact are -ep/m1 and +ep/m2.

That is much simpler than working in a different reference frame.
 

Related to Choice of reference frame in conservation of momentum/energy problems

1. What is the significance of choosing a reference frame in conservation of momentum/energy problems?

The choice of reference frame is crucial in solving conservation of momentum/energy problems because it helps to simplify the calculations and understand the physical scenario better. It also ensures that the laws of conservation of momentum and energy are properly applied and the final results are accurate.

2. How do you choose the most appropriate reference frame for a conservation of momentum/energy problem?

The most appropriate reference frame is one in which the motion of the objects involved is the simplest. This means that the reference frame should have the least amount of motion or should be at rest. It should also be chosen in such a way that the objects involved move in a straight line or at constant speeds.

3. Can the choice of reference frame affect the final result in a conservation of momentum/energy problem?

Yes, the choice of reference frame can affect the final result in a conservation of momentum/energy problem. If the reference frame is not chosen correctly, the final result may not be accurate. This is because the laws of conservation of momentum/energy may not be properly applied in an incorrect reference frame.

4. Can multiple reference frames be used in a conservation of momentum/energy problem?

Yes, multiple reference frames can be used in a conservation of momentum/energy problem. In some cases, it may be necessary to switch between reference frames in order to simplify the problem or to understand the motion of the objects involved better. However, it is important to ensure that the laws of conservation of momentum/energy are consistently applied in all reference frames used.

5. How does the choice of reference frame affect the understanding of the physical scenario in conservation of momentum/energy problems?

The choice of reference frame can greatly affect the understanding of the physical scenario in conservation of momentum/energy problems. A well-chosen reference frame can help to visualize the motion of the objects involved and understand how the laws of conservation of momentum/energy apply. It can also help to identify any external forces or factors that may affect the problem.

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