# Homework Help: SuM heLp wUd b appRecIatEd

1. Jan 23, 2005

### aptiva

A subatomic particle moving at a speed of 5.5*10^7 m/s has a life of 3.1*10^-5 seconds. what is the lifetime of this aprticle when it is at rest? ...does anyone know what formula i would use to solve this one?

2. Jan 24, 2005

### vincentchan

this is the most basic problem in relativity.... are you having a hard time understanding relativity or you just can't figure out how to do this problem....
relativity usually puts in a advance physics class. since you are learning relativity now, i believe you have already suffer through the classical mechanic and electrostatic and thermal physics those basic stuff.... and you have already develope a skill to deal with physics problems. This problem is not tricky at all. plug the number in appropiate formulas and the answer will shown up instantly.... if you really can't do this problem, at least show me some of your work or let me know which part you stuck in....

3. Jan 24, 2005

### hype_chicky

i dunt understand the question the only thing i can find in the textbook is that rest mass is the mass measured at rest to the observer and that in the equation p= mv/ square root 1-v^2/c^2 m is what the rest mass is but i dunt understand how to apply the equation

4. Jan 24, 2005

### dextercioby

Vincentchan,did u copy-pasted the message from the other thread??It looks remarkably similar... :tongue2:
To the OP:Do you know any formula involving time dilation in special relativity???

Daniel.

5. Jan 24, 2005

### vincentchan

dex.. aptiva and chicky is the same person... and he posts these 3 problems in 5 to 6 different places in this forum...

6. Jan 24, 2005

### dextercioby

So we're dealing with an identity crisis,huh??? :tongue2:

Daniel.

7. Jan 24, 2005

### iodmys

Someone should tell this retard that "dunt" is spelled "don't" or "do not" and that "I's" should be capitalized.

8. Jan 24, 2005

### hype_chicky

all u nerds shud...das right SHUD not SHOULD kiss my ass

9. Jan 25, 2005

### iodmys

Where are the moderators? Seriously, this person needs to be dealt with. Why not remove the entire thread?

Last edited: Jan 25, 2005
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