- #1
mmmboh
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Hi, I have an assignment due in the morning, and it is complete, there is just one tiny thing I am unsure of: In a rest frame, a mass m moves west at speed v, and another mass also m moves east at speed v. Now consider the setup as viewed by an observer going west at speed u.
I had to find the total energy in each of these frames, and I did, and now I have to say in which frame the total energy is bigger...that's the problem, the equations are not simple and I can't tell by looking at them!
Conceptually I would probably assume it is bigger in the rest frame, because the relative velocity of the two masses in the rest frame is 2v, and I think this relative velocity is smaller in the moving frame, because that's how velocity addition works, or at least in this case, where they are moving in the same direction with respect to u. But someone else told me it is bigger in the moving frame.
Who is right?
I had to find the total energy in each of these frames, and I did, and now I have to say in which frame the total energy is bigger...that's the problem, the equations are not simple and I can't tell by looking at them!
Conceptually I would probably assume it is bigger in the rest frame, because the relative velocity of the two masses in the rest frame is 2v, and I think this relative velocity is smaller in the moving frame, because that's how velocity addition works, or at least in this case, where they are moving in the same direction with respect to u. But someone else told me it is bigger in the moving frame.
Who is right?
