- #1
Tim Wu
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- 0
I find this problem kind of tricky. I think it must be a, since a change in momentum of the car causes the same change in momentum of the earth.
Is Conservation of Energy the Key to Solving This Tricky Problem?
- Thread starter Tim Wu
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Homework Help Overview
The discussion revolves around a problem related to the conservation of momentum and energy, specifically examining the relationship between the momentum of a car and the Earth. Participants are exploring the implications of momentum changes and their effects on kinetic energy.
Discussion Character
- Conceptual clarification, Mathematical reasoning, Assumption checking
Approaches and Questions Raised
- Participants are analyzing the relationship between momentum and kinetic energy, questioning whether a change in momentum implies a change in kinetic energy. They are comparing relevant formulas and discussing the implications of mass differences between the car and the Earth.
Discussion Status
The discussion is active, with participants engaging in mathematical reasoning and clarifying concepts. Some have provided insights into the calculations involved, and there is a recognition of the differences in kinetic energy due to mass disparities. However, there is no explicit consensus on the correctness of specific options presented in the problem.
Contextual Notes
Participants are working within the constraints of a homework problem, which may limit the information available for a complete analysis. Assumptions regarding the system and the definitions of momentum and kinetic energy are being questioned.
I find this problem kind of tricky. I think it must be a, since a change in momentum of the car causes the same change in momentum of the earth.
- #2
Doc Al
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That part is correct. But does that imply that the kinetic energy is the same? Compare the formulas for momentum and kinetic energy.Tim Wu said:
- #3
Tim Wu
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- 0
Oh yeah! Ek=1/2*m*v^2, and v = p/m, therefore Ek= p^2/2m. Since p is the same for car and Earth but the Earth's mass is way bigger the kinetic energy gained by Earth wud be much lower! So would option c be right?Doc Al said:
- #4
Doc Al
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You got it. Good thinking!Tim Wu said: