Special Relativity, equation help needed

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SUMMARY

The discussion focuses on deriving the relativistic mass equation from the energy-momentum relation in special relativity. The equation E² = c²p² + m₀²c⁴ is utilized to show that m = (p²c² - T²) / (2Tc²), where p is the relativistic momentum and T is the kinetic energy. The user attempts to manipulate the equations but concludes that their result yields mo instead of m, indicating a potential issue with the problem statement itself. The conclusion is that the user's mathematical approach is correct, but the problem may contain an error.

PREREQUISITES
  • Understanding of special relativity concepts, particularly energy and momentum.
  • Familiarity with the equations E = T + m₀c² and E² = c²p² + m₀²c⁴.
  • Knowledge of relativistic momentum defined as p = γm₀u.
  • Basic algebraic manipulation skills to rearrange and simplify equations.
NEXT STEPS
  • Review the derivation of the energy-momentum relation in special relativity.
  • Study the implications of relativistic mass versus rest mass in physics.
  • Explore common problems and solutions related to kinetic energy in relativistic contexts.
  • Investigate potential errors in problem statements in physics textbooks or assignments.
USEFUL FOR

Students studying physics, particularly those focusing on special relativity, educators preparing problem sets, and anyone interested in the mathematical foundations of relativistic mechanics.

punkstart
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Given that E2 = c2p2 + mo2c4-----------(1);
where p represents the relativistic momentum p=[tex]\gamma[/tex]mou,
show that m=(p2c2-T2)/(2Tc2) where m is the relativistic mass of the particle,and T it's kinetic energy.



Homework Equations



E= T+moc2-------(2)

The Attempt at a Solution



I start by saying p2c2= E2-mo2c4 (from (1)), subtracting T2 from both sides gives
p2c2 -T2 = E2-mo2c4-T2 . Now using (2) i expand E;

p2c2 -T2= (T+moc2)2-mo2c4 -T2 which gives
p2c2 -T2= T2+2Tmoc2+mo2c4 -mo2c4 -T2; simplifying

p2c2 -T2 = 2Tmoc2 Now dividing by 2Tc2 gives

(p2c2-T2)/(2Tc2) = (2Tmoc2)/(2Tc2) I now have the required LHS of (1),

This yields (p2c2-T2)/(2Tc2) = mo , NOT m !

Where have i gone wrong !??
 
Physics news on Phys.org
Your work looks fine to me. The problem appears to be wrong.
 

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