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Newtons Balls
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Homework Statement
A particle has 4-momentum:
P[tex]^{u} [/tex] = c(2[tex]\sqrt{2} [/tex],1,0,-1)
Where c denotes the speed of light.
Calculate the particle's rest mass m, its energy E, its speed v and its kinetic energy T.
Homework Equations
Well the relativistic relation between E, m and p is:
[tex]m^{2}[/tex] = [tex]E^{2}[/tex] - [tex]p^{2}[/tex]
The Attempt at a Solution
I know this is meant to be really easy but this 4-momentum stuff is confusing me rather allot :/
The notation I've seen in my textbook indicates the 4th component should be the temporal component. The textbook also seems to indicate that the temporal component is equal to mc and E/c. This would give negative energy and negative mass, which I don't think is correct- am I misunderstanding what the textbook is saying?
After doing a bit of reading I've seen things saying that the 4-momentum inner producted with itself is related to the rest mass of the particle like this:
[tex]-|p|^{2}=m^{2}c^{2} [/tex]
1) is this relationship correct?
2) I haven't actually managed to find anything explicitly saying what the inner product in Mikowski space is, would it be the standard dot product still?
3) if the relationship is correct do I use all four components in this dot product or just the first three?
I'm a bit rubbish at this stuff, I'm trying to teach myself the course from a textbook and whilst its quite good at explaining the kinematic aspects I'm having trouble following it when it gets onto mass/energy relationships...
Thanks
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