How Does Velocity Affect Mass in Relativity?

AI Thread Summary
In the discussion about how velocity affects mass in relativity, a problem is presented where a man weighing 78 kg on Earth is considered on a starship traveling at 0.93c. The formulas for relativistic mass change are discussed, specifically M = Mo / √(1 - v^2/c^2). Using this formula, the calculated relativistic mass is approximately 212.2 kg. The conversation confirms the distinction between weight and mass, emphasizing that the problem states weight, but the solution focuses on mass. The final answer of 212.2 kg is presented as the correct working.
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Homework Statement



On Earth a man weights 78kg. what is his weight on a starship which is traveling at 0.93c?


Homework Equations



Are the following correct for mass change in terms of relativity?

mr = E/c2
m0 = sqrt(E2/c4 - p2/c2)

Where E is energy, p is momentum and c is the speed of light in vacuum

Need help solving this!
Thank you in advance!
 
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Are you sure the problem is stated as weight? Because, if it is, then the solution is pretty simple...

If it says "mass", then we can do more... :)
 
yes it states weight and i think i have an idea of how to do it using the formula
M= Mo / [√ 1 - v^2/ c^2]
where Mo is 78kg and velocity is 0.93c
M= 78 / [√ 1 - (0.93c^2)^2/ c^2]
M= 78 / [√ 1 - 0.93c^2]
M=212.2105291kg

So the weight would be approximately 212.2 kg

is this correct working and answer?

thank you in advance~!

s
 

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