# Recent content by Amio

1. ### Can subatomic particles be PROVED to exist?

I just love philosophy. So if you (and the mentors) never mind for this occasion... I guess I can't deny my existence. Cause the moment I deny it is actually the moment I accept it for proving the existence of my denial. So I exist. ["I think, therefore I am." - Rene Dascartes] Okey I admit this...
2. ### A question on Dimensional analysis

Thanks. So I conclude - dimensional analysis works for equations; but it will work for proportionality only if the constant is unit less. (The book was a bit confusing.)
3. ### A question on Dimensional analysis

It never seems to be the case. Serway's book describes it as a general procedure. Here is the excerpt from Serway's book:(as this page can be previewed in amazon; I think it never breaks any copyright) Now this certainly works for x ∞ (a^n)(t^m); but what happens when we apply this for...
4. ### A question on Dimensional analysis

Wait, I have another question. In law of gravitation we know F = GmM/r^2 Here G is a proportionality constant, isn't it? Then how come it is not a pure number (ie it has units like) 6.67×10^−11 N·(m/kg)2 ?
5. ### A question on Dimensional analysis

OOPPss... Suddenly I understand. k is not anything like length mass or time, right? Maybe thats the reason why they left out k?
6. ### A question on Dimensional analysis

This is actually an example from Physics for Scientists and Engineers by Serway. I am confused about the way they solved it. Homework Statement Suppose we are told that acceleration a of a particle moving with uniform speed v in a circle of radius r is proportional to some power of r, say...
7. ### Concept of Free Fall in question!

As Nugatory said, objects of different masses feel different gravitational force. Now, I think your confusion is, if masses feel different magnitudes of gravitational force how come they accelerate at same rate? Right? In other words you are asking if F is different how can g be same? You...
8. ### Wool vs Cotton - electronegativity?

For both reasons; I think. Cotton is more electronegative (then wool) implies Cotton atoms' (outer shell) electrons are more tightly held than wool. Wool is less electronegative (then cotton) implies Wool atoms' (outer shell) electrons are more loosely held than cotton.
9. ### Is Time a vector quantity?

I think I got the idea. Thanks everyone.
10. ### Is Time a vector quantity?

That post clarifies a lot.
11. ### Is Time a vector quantity?

Well, well... I think I should take a break. :-)
12. ### Is Time a vector quantity?

Hey, thanks a lot. :-) But I wonder why while writing intro physics books they never clarify this. I started this thread just for kicks but in the end I have learned something important.
13. ### Is Time a vector quantity?

Sorry, but I dont understand this. For example: the unit vector along x axis is a 1D vector. Did you mean to say that its actually a scalar? And also,
14. ### Is Time a vector quantity?

I am beginner intro physics student. So I might be lacking in concept. That said; when we study 1D kinematics don't we consider 1D quantity like 1D velocity. 1D acceleration as vectors?
15. ### Is Time a vector quantity?

If we multiply velocity with time, we get displacement. How can we multiply two vector and get a vector? (I thought it is possible only under cross multiplication, but you reminded me that cross multiplication is only for 3D.) So how do we multiply the 'vector' time with any other vector...