Search found 57 matches

by SMMamun
Tue Feb 11, 2014 2:45 pm
Forum: Physics
Topic: Falling Body, Thought Experiment
Replies: 2
Views: 1605

Re: Falling Body, Thought Experiment

You cannot arrive at any of the equations ($F=G\frac{Mm}{R^2}$, $a=\frac{F}{m}=\frac{GM}{R^2}$, $t=\sqrt{\frac{2h}{a}}$) just by logic and the information provided in the question. The equations are in fact the result of experiments, historically many years of various experiments and observations. T...
by SMMamun
Mon Feb 10, 2014 8:51 pm
Forum: Physics
Topic: Falling Body, Thought Experiment
Replies: 2
Views: 1605

Falling Body, Thought Experiment

Is it possible to prove just by Thought Experiment (pure logic, no actual experiment) that a heavy object and a light object dropped from a certain height at a certain moment shall reach the ground at the same moment? [Imagine a simple scenario: no air or other medium to resist the motion of the obj...
by SMMamun
Sun Dec 08, 2013 7:34 am
Forum: Physics
Topic: About relativity
Replies: 8
Views: 3215

Re: About relativity

Dear Adil, Your questions, although sounding simple, are thought-provoking and require a critical analysis of the historical development of relativity theory for comprehension. However, I am providing a brief summary: 1. Why Einstein took the speed of light for relativity? It was a common belief in ...
by SMMamun
Thu Nov 28, 2013 9:55 pm
Forum: Higher Secondary Level
Topic: dividing $x^{2013}-1$
Replies: 7
Views: 3641

Re: dividing $x^{2013}-1$

Solution Let the dividend $f(x)=x^{2013}-1$, when divided by the divisor $d(x)=(x^2+1)(x^2+x+1)$, give us the quotient $q(x)$ and the remainder $r(x)$. Thus $f(x)=q(x)d(x)+r(x) ... ... ...(1)$ Since $d(x)$ is a 4-degree polynomial, $r(x)$ will, at best , be a 3-degree polynomial. So, let $r(x)=ax^3...
by SMMamun
Tue Nov 19, 2013 10:39 pm
Forum: Higher Secondary Level
Topic: dividing $x^{2013}-1$
Replies: 7
Views: 3641

Re: dividing $x^{2013}-1$

@sowmitra,
A 3-degree polynomial should have the form:
$$Ax^3+Bx^2+Cx+D$$
Therefore the remainder cannot be right.

The error is also (consequently) evident if we put the value of $C=-1$ in equation $(4)$ or $(5)$ rather than in the equation $A+C=0$.
by SMMamun
Sun Nov 10, 2013 3:01 am
Forum: Higher Secondary Level
Topic: Coordinate Geometry, Straight Line
Replies: 2
Views: 1670

Re: Coordinate Geometry, Straight Line

I am not fully solving the problem, but showing you the necessary steps that should be sufficient. 1. Rewrite each equation in its normal/perpendicular form. Keep the $±$ signs for now. 2. Let the normals on the lines from the origin $O(0, 0)$ respectively make angle $α_1$ and $α_2$ with positive $x...
by SMMamun
Mon Oct 21, 2013 8:19 pm
Forum: Physics
Topic: About relativity
Replies: 8
Views: 3215

Re: About relativity

শূণ্যস্থানে c সর্বদা ধ্রুব থাকে। এ মান দর্শকের স্থিতি বা গতিশীলতার উপর নির্ভর করে না। Yes, according to the prevailing view in physics, the speed of light in vacuum relative to any observer is always $c$ (i.e. 299,792,458 m/s), regardless of the motion of the observer. But it is important to rememb...
by SMMamun
Mon Oct 14, 2013 8:12 pm
Forum: Physics
Topic: About relativity
Replies: 8
Views: 3215

Re: About relativity

If the question is exactly as you wrote, then it is ill-defined. Because when speaking about a speed, we must first specify the reference object with which the speed has been considered. Therefore, “তুমি একটি রকেটে করে আলোর বেগে যাচ্ছ” is not a clear statement as there is no mention of the reference...
by SMMamun
Fri Jun 28, 2013 3:38 pm
Forum: Physics
Topic: Time traveling
Replies: 2
Views: 1577

Re: Time traveling

There are different meanings of time travel – for example, observing but not interacting with events in the past, or both observing and interacting with them. Also, what do you mean by 'It is possible to go to future by time traveling'? If we understand your question (either observing or interacting...
by SMMamun
Fri Mar 15, 2013 5:48 pm
Forum: Number Theory
Topic: fermat's last theorem
Replies: 4
Views: 1432

Re: fermat's last theorem

In that case, just questioning whether "the cases of prime numbers CAN be proved" might give the impression that any proof of Fermat's Last Theorem is still incomplete and requires further proof for the cases of primes, but, as I said earlier, this has already been done (by Wiles and Taylor) and the...