Physics Problem Solving Marathon

Discuss Physics and Physics Olympiad related problems here
User avatar
sm.joty
Posts: 327
Joined: Thu Aug 18, 2011 12:42 am
Location: Dhaka

Physics Problem Solving Marathon

Unread post by sm.joty » Mon Jan 02, 2012 12:21 am

The Physics Olympiad is knocking at the door. So I think it is high time to start a Physics problem solving marathon.
I informed Moon vai, Emroz vai & others. But they were busy. But now moon vai is free. So I think Moon vai can help us.

There are some rules from me but if there anything to add then Moon vai or other Moderators will add them.
Rules:-
1.Very simple.I'll start this Marathon with a physics problem. Next who can give the solution of the problem, will get a chance to post a new problem. Different solutions are welcome too. Who will give a different solution also can get a chance to post a new problem.

2.If you post the problem from any other Olympiads or books then you should mention the name of the source.

3.You can not post any contest's problem before expiring the deadline of the contest.

4.If anyone's solution is somewhat wrong, another person posts the correct solution and then solution for the second problem and hides it. Then he posts another problem.

5.We should mention the serial number of the problem or solution like "Problem-1","Problem-120" and "Solution-1","Solution-45"

6.No one should post reply without full solution.

7. It's essential to use LATEX.

8.If any problem contains with many different parts like a),b),c) then you can post any of them (if you can't solve others.)

9.You can use Bangla or English but can't use banglish and you should use only one language for one post.Don't mix Bangla and English
I hope everybody will enjoy it. :D
Last edited by sm.joty on Mon Jan 02, 2012 12:43 am, edited 1 time in total.

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

Re: Physics Problem Solving Marathon

Unread post by sm.joty » Mon Jan 02, 2012 12:36 am

The first problem.
A very easy problem for all. :D
Problem-01:-
A stone thrown from the top of a building is given an initial velocity of $20 ms^{-1}$ straight upward. The building is $50m$ high.The stone reach at the maximum height and then the stone falling freely.
Determine,
a)the maximum height ?
b)the time at which the stone returns to the height from which it was thrown ?
c)the time when the stone will reach at the ground ?


Source: Fundamentals of Physics by Halliday-Resnick.
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

User avatar
amlansaha
Posts: 100
Joined: Tue Feb 08, 2011 1:11 pm
Location: Khulna, Bangladesh
Contact:

Re: Physics Problem Solving Marathon

Unread post by amlansaha » Tue Jan 03, 2012 2:11 pm

hint:
$h=ut-\frac{1}{2} gt^2; v^2=u^2-2gh$ :)
অম্লান সাহা

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

Re: Physics Problem Solving Marathon

Unread post by sm.joty » Tue Jan 03, 2012 9:01 pm

Amlan da, it's a marathon so better if you post full solution. :)
But the hint is ok.
And of course don't forget to post a new problem here. :D
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

Ipsc palash
Posts: 35
Joined: Sat Oct 22, 2011 11:46 pm
Location: Ispahani Public School And College. Comilla ,Bangladesh

Re: Physics Problem Solving Marathon

Unread post by Ipsc palash » Thu Jan 05, 2012 1:16 pm

NEW PROBLEM POST KOREN NA KENU

Ipsc palash
Posts: 35
Joined: Sat Oct 22, 2011 11:46 pm
Location: Ispahani Public School And College. Comilla ,Bangladesh

Re: Physics Problem Solving Marathon

Unread post by Ipsc palash » Thu Jan 05, 2012 1:18 pm

বাংলিশের জন্য দুঃখিত। MISTAKE

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

Re: Physics Problem Solving Marathon

Unread post by sm.joty » Thu Jan 05, 2012 5:28 pm

Solution-01:
a) $H=\frac{v_{0}^2}{2g}=20.4$

b)$T=\frac{2v_{0}}{g}=4.08$

c)$h=50+20.4=70.4$,
$t=\sqrt{\frac{2h}{g}}=5.83$
Problem-02:
The problem is from 2nd IPhO-1968.
It's not so hard with respect other IPhO problems.;) So keep trying :)
Attachments
Problem-2.pdf
IPhO-1968
(19.49 KiB) Downloaded 271 times
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

User avatar
amlansaha
Posts: 100
Joined: Tue Feb 08, 2011 1:11 pm
Location: Khulna, Bangladesh
Contact:

Re: Physics Problem Solving Marathon

Unread post by amlansaha » Thu Jan 05, 2012 10:47 pm

sm.joty wrote: Problem-02:
The problem is from 2nd IPhO-1968.
It's not so hard with respect other IPhO problems.;) So keep trying :)
এইটা মনে হয় IPhO এর ইতিহাসের অন্যতম সোজা সমস্যা(এই কারণেই মনে হইছে, কারণ আমি প্রবলেমটার একটা সলুশনের উপায় বাইর করছি :D)
অম্লান সাহা

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

Re: Physics Problem Solving Marathon

Unread post by sm.joty » Fri Jan 06, 2012 12:39 am

আসলেই সোজা। :D একটু চিন্তা করলেই হয়।
আর সোজা বলেই দিলাম। ;)
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

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

Re: Physics Problem Solving Marathon

Unread post by sm.joty » Sat Jan 07, 2012 12:02 pm

কি ব্যাপার কেউ এখনও সমাধান দিল না ??? বেশি কঠিন নাকি ? :D
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

Post Reply