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.
iaberrant
Messages
13
Reaction score
0

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!
 
Physics news on Phys.org
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
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top