## Need help with an equation

For students of class 11-12 (age 16+)
Fahim
Posts: 2
Joined: Sun Jan 01, 2012 5:02 am

### Need help with an equation

I didn't where to post this, but anyway I was reading Zafar Iqbal's book on theory of relativity @ http://www.deshiboi.com/listing_summery ... ing_id=581 and One thing I didn't get is this at page 11 it says
Untitled.png (402.6 KiB) Viewed 2692 times
$t=\frac{\sqrt{v^2t^2+D^2}}{c}$

that can also be written as
$c^2t^2=v^2t^2+D^2$
or
$c^2-v^2=D^2$

How do you get the third result $c^2-v^2=D^2$ from?

I know I am missing something, can you guys help me? Thanks

Moon
Posts: 751
Joined: Tue Nov 02, 2010 7:52 pm
Contact:

### Re: Need help with an equation

Apparently this is a typo. We have $(c^2-v^2)t^2=D^2$. In fact, $c^2-v^2=D^2$ is dimensionally incorrect.
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin

learn how to write equations, and don't forget to read Forum Guide and Rules.

sm.joty
Posts: 327
Joined: Thu Aug 18, 2011 12:42 am
Location: Dhaka

### Re: Need help with an equation

আমার জানা মতে এটা একটা প্রিন্টিং মিস্টেক। (মুন ভাই যেটা বলল)
খেয়াল করলে দেখবা মিউওন এর কথা লেখার সময় কিন্তু এমন একটা ভুল আছে।
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

Fahim
Posts: 2
Joined: Sun Jan 01, 2012 5:02 am

### Re: Need help with an equation

Thanks so much @Moon and @sm.joty

It makes sense now. @sm.joty can you also tell me typo for Muon, Thanks!

sm.joty
Posts: 327
Joined: Thu Aug 18, 2011 12:42 am
Location: Dhaka

### Re: Need help with an equation

Actually at this moment I haven't the book. So can't help you now but if you read carefully all the equation then you will find a bug in "MUON".
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

sm.joty
Posts: 327
Joined: Thu Aug 18, 2011 12:42 am
Location: Dhaka

### Re: Need help with an equation

sm.joty wrote:Actually at this moment I haven't the book. So can't help you now but if you read carefully all the equation then you will find a bug in "MUON".
Oups there's a grammatical mistake.
Whatever actually this time I don't have this book so I can't help you @Fahim.
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........