Math Help

[NuclearSilo]

v/t is acceleration but sadly were not talking about it

[!G4!]

ok wow i see knw lol ^^

[Barotix]

v/t is acceleration but sadly were not talking about it

yeah I noticed, thats why I changed the equation I was using.

[Kazaxat]

it appears like u are right

im sure im right

but oh well i will start looking at the problem again tomorrow with a fresh mind.

That's correct, you would be right...
...If only the problem was not related to rates and distance.

Proportions are for other types of problems that don't have a reciprocal relationship.
For example, if you had a problem like this:

"Bob worked 6 hours and made $30. How long would he have worked if he made $45?"

Setting up a proportion would in this kind of problem since money gained depends directly on hours worked.
6/x = 30/45

Therefore, you do 45 x 6 / 30 = 9 hours. See?
The reciprocal property does not apply to fixed rates. The hours worked and money gained do not influence each other like rate and distance do. Do you understand?

More time worked = More money
Less time worked = Less money
1.5x time worked = 1.5x money

Whereas, like I said before,

Faster rate = Less time to get there
Slower rate = More time to get there

They are different things. You were actually partly correct but unfortunately mislead. Speed and distance problems have their own little equation; D = RT.

6/30km = x/45km

so 9 hours.

@Grandpa:
mmk

[NuclearSilo]

That's why I said u are 10 years old kid, stubborn

[Grandpa]

That's why I said u are 10 years old kid, stubborn

So many here are "right". Cookies to everyone!

Einstein wrote:
"Imagination is more important than knowledge..."

"Gravitation cannot be held responsible for people falling in love. How on earth can you explain in terms of chemistry and physics so important a biological phenomenon as first love? Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity."

[Kazaxat]

That's why I said u are 10 years old kid, stubborn

So many here are "right". Cookies to everyone!

Einstein wrote:
"Imagination is more important than knowledge..."

"Gravitation cannot be held responsible for people falling in love. How on earth can you explain in terms of chemistry and physics so important a biological phenomenon as first love? Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity."

LMFAO good quote

[Grandpa]

LMFAO good quote

Ahhhh?? Kazaxat? Don't be too quick to laugh:

Spoiler!

To Kazaxat:

ABOUT NON-SEQUITURS:
I have read the entire thread you mentioned, called ( To Smart People: Help ) and now understand that both your questions about 'displacement' and your statements about relativity in this thread about Math Help were non-sequiturs. This is something you seem to have a great proclivity for and I can see that it oftentimes works to your advantage. To use my own non-sequitur, I love my youngest son very much, but he can be very annoying (sometimes). He just turned 21 and has done 'this' all his life. I am now convinced that he used to do it on purpose (probably as an attention getting device). Do you? He struggles even today to stop his habit of purposeful over-irritation. Will you someday? I hope so. I doubt it can ever be done utterly; I can certainly not claim this even though I have struggled with it personally for almost 40 years.

OTHER LOGICAL FALLACIES:
What you likely did was draw a "Hasty Generalization" when you were speaking to Barotix.
You also committed a Cum Hoc Ergo Propter Hoc fallacy.
Another example of this second type of fallacy can be seen on the "Church of the Flying Spaghetti Monster" website. So unless you were trying to say something like "Pirate Populations vs. FSM's and Global Warming" are the same as "Displacement vs. Relativity while Helping People with Their Homework", it might be best to keep those types of observations to yourself. Briefly stated, correlation does not prove connection.

SOME CONCLUSIONS (and one digression):
Barotix was trying to help in this thread (and elsewhere) and didn't need your interference. I'm sure you were (in your own way) also trying to help before you got side-tracked, and that wasn't seen as being helpful. The same could be said of my participation, so don't feel too bad, but I am for certain gonna take Judge's advice ( found > HERE < ) and not post in that thread (lol, unless I have a positive contribution). The only thing that bothers me in the 'smart people' thread you mentioned is when (given reverse engineering enuf data) I cf. the 2D graph and the 3D graph is that Chinese and European skill learning rates are not equal. But and of course that is my own non-sequitur. Irrelevant Conclusions (also called Ignoratio Elenchi) - and sometimes referred to as red herrings are all logical fallacies and they (as a whole) just don't matter. What non-sequiturs (from Latin, meaning 'it follows') and Irrelevants and Ad Hominem (Personal Attack) have in common is that they pretend to relate to the subject when they in fact they simply do not.

ALTERNATIVES:
You could have stopped for a second and thought about it before posting thus negating what I saw as a need for being a mediator in yet another argument. Consider for instance, that what the "smart people" were talking about when they mentioned displacement was the amount of AIR that was displaced when various bodies fell under differing rates of acceleration. There were two examples given in the "smart people" thread:

1. One was "free-fall" acceleration
2. The other was mechanically induced by a spring

You could have used your inductive reasoning process to conclude that Barotix was referring to distance and suffered only a moment's confusion (something we all are subject to) when he "went to check" and spared him the trouble of replying to your inquiry.

Regarding your shoving match with NuclearSilo seen here and there. I'd like you to think about the last time you saw a big dog with a little dog. In my opinion you guys are both smart and in all likelihood are both above average in intelligence, but Big Dogs don't fight with puppies, they'd kill 'em

YEAH? SO? (What about you, Gramps?):
In terms of "ALTERNATIVES" I didn't have to speak to you about this -or- relativity -or- to anyone about algebra for that matter, but consider the effort to be worthwhile and hope you see this as a compliment (to your innate intelligence).

Also of note might be that I've committed a logical fallacy (on purpose) here. Did you spot it? It's sometimes called a Bifurcation or "Black & White" fallacy. It happens when only two possible options are given and there are in fact more than two. When I asked, 'Did you?' [post what could be termed 'annoying' remarks] on purpose, it too was a logical fallacy because it didn't list all the options, like "my brother got on my comp and posted ". This same question also contained a Complex Question fallacy; that happens when the question contains false assumptions that endorse themselves like "Have you stopped beating your wife?" or "Will you ever stop peeing in the closet?". Hope you liked it, it wasn't meant as a personal attack. You get "C" to the second power from me, that is: ( cookies )² , for humor value. BTW, I'm not a doctor, but I watched an actor play one on TV. I have worked in the IT department of a billion dollar insurance company for more than 12 years as a Computer Analyst and have played WOW since beta, so even though I am still a newb on SRO, I know what it means if somebody says, "Grandpa crits with a wall o' text"! (it can also be called 'Key-J's secret') -but- the one that I (like you apparently) couldn't figure out for the longest time was 'STFU'; I thought it meant what it sounded like: "stuff you".

~Grapns

I noticed that although you demanded answers you failed to thank anybody.
From my observations that is simply not like you.
No milk from me to go with your cookies.

Thanks though, I am now one post closer to my goal of 100.

~Grandpa

[Grandpa]

v/t is acceleration but sadly were not talking about it

yeah I noticed, thats why I changed the equation I was using.

Where v = velocity
and t = time
and a = acceleration
v ÷ t ≠ a

Acceleration:
a = the Time (t) rate of change of Velocity (v).

Spoiler!

Velocity (v) is defined in terms of direction and speed.
Velocity is a vector or directed quantity. Meaning that the definition of (v) involves terms like magnitude (how much faster, or how much slower and for what period or periods of time and at what specific rates) and direction. Velocities change by speed increase or decrease (changes to magnitude) -and/or- by any change of direction.

Consider escape speeds (after discounting interference and displacement) needed to overcome earth's gravitational force and go past orbit speeds. Because they are scalar it's not proper to call them "velocities" and to do so is a misnomer. They are independent of direction not changed by coordinate system rotations (in Newtonian mechanics) or by Lorentz transformations (in relativity).

For Basic Algebra questions like this:

• A journey takes 6 hours if John travels 30km/h. How long will it take him if he travels at 45km/h ?

This (and questions like it) only need be solved for single variables.
One can rightly assume constant speeds and (as you've stated) equal distances.
Introduction of ancillary formulae is generally not needed, but if the student wants to, it's best to do so flawlessly.

~Grandpa

[Barotix]

v/t is acceleration but sadly were not talking about it

yeah I noticed, thats why I changed the equation I was using.

Where v = velocity
and t = time
and a = acceleration
v ÷ t ≠ a

Acceleration:
a = the Time (t) rate of change of Velocity (v).

Spoiler!

Velocity (v) is defined in terms of direction and speed.
Velocity is a vector or directed quantity. Meaning that the definition of (v) involves terms like magnitude (how much faster, or how much slower and for what period or periods of time and at what specific rates) and direction. Velocities change by speed increase or decrease (changes to magnitude) -and/or- by any change of direction.

Consider escape speeds (after discounting interference and displacement) needed to overcome earth's gravitational force and go past orbit speeds. Because they are scalar it's not proper to call them "velocities" and to do so is a misnomer. They are independent of direction not changed by coordinate system rotations (in Newtonian mechanics) or by Lorentz transformations (in relativity).

For Basic Algebra questions like this:

• A journey takes 6 hours if John travels 30km/h. How long will it take him if he travels at 45km/h ?

This (and questions like it) only need be solved for single variables.
One can rightly assume constant speeds and (as you've stated) equal distances.
Introduction of ancillary formulae is generally not needed, but if the student wants to, it's best to do so flawlessly.

~Grandpa

lolwut?

As did others. Their answer (and equation) is the same as mine.

x = v*t
v = 30km/h
t = 6 hours

x = (30km/h)*(6h)
x = 180km

now don't you have one unknown you can solve for the other (t).

t = x/v
v = 45km/h
x = 180km
t = (180km)/(45km/h)
t = 4

very simple

.....
A isn't mentioned >_> [emo]I AM SO MISUNDERSTOOOOOOD! [/emo]
x can be used to replace d, distance. Thats how I was taught

Can't remember cba to check textbook, but doesn't
a = (vi-vf)/t

therefore

a = vavg/t??

???

[NuclearSilo]

v = dx/dt
a = dv/dt

When v is constant u can assum that v = d/t and when a is constant u can assum that a = v/t

[Grandpa]

Your comments are welcome, I meant zero offense.
This whole conversation was 'carried away' by 'you-know-who' and me also, but for me it was fun.
My sis calls me "brat" to this day. She's pushing 60 (this June - but don't tell her I said that), ya know?

Try checking your equations so they fit both Newton and Einstein (if you wanna) but in the meantime go easy on the old guy - I took physics in the 70's. Oh, click the 'spoiler' in my msg to 'you-know-who' earlier for a real wall-o-text.

~Granps

[ciko1984]

man what are you doing (didn't read all but wtf) lets draw it this is road x km
A-----------B distance is x now if john drives 30km/h it takes 6 hours so 6x30=180 km this is distance, if speed is 45km/h then 180/45=4h i dunno what you are talking about (no offense )

[Grandpa]

man what are you doing (didn't read all but wtf)

That's ok - my first post is > HERE <
The prob's solved.

What I was speaking about was velocities in terms of Relativity introduced needlessly by another participant to this discussion.

Spoiler!

The basal principle of all uniform motion rightly applies if the trains were on large space ships while they were approaching the speed of light in a vacuum ("C") with differing velocities. Velocity is defined in terms of direction and speed but even if speed and acceleration were equal, as long as the two ships had different vectors 'relativity' and Einstein's "Law of Optics" would rightly apply.

Einstein states the Law of Inertia as follows:

"A body removed sufficiently far from other bodies continues in a state of rest or of uniform motion in a straight line."
o Albert Einstein (1879–1955). Relativity: The Special and General Theory. 1920. (p. 13)


This law is important because the Newtonian Mechanics do not hold for a system where this law does not hold.
Since we can rightly assume that John and the train or trains in question were on earth, at the time of the test, your answer (X=4) is correct.

Discussion synopsis:

• somebody said: I'm pretty sure this has to do with displacement.
• somebody else said:
  solving for x...
  45*6 = 30x
  x= 270/30
  x = 9 hours
  see?
• then came as that side-track got started:
  
  • so, let me get this straight. If you're traveling the same distance at a greater velocity it should take you more time?
    
  • THE REPLY: yes something to do with einstein theory of relativity and frame of reference. u dont know about that?
    i already solved it
    X=9
• Yet another party to the discussion said:
  wtf children nowadays are so dumb Oo
  @TwoKay: u dont need to write that much, u'll get penalty point in exam.
  
  Just explain as simple as ILoveQuack did:
  d=vt=30*6=45*x => x=180/45=4

-----------------
ME? Okay, I kinda butted in... but not until after we all did well for the elementary algebra prob.
but and again, my first post can be found > HERE <

[Barotix]

Your comments are welcome, I meant zero offense.
This whole conversation was 'carried away' by 'you-know-who' and me also, but for me it was fun.
My sis calls me "brat" to this day. She's pushing 60 (this June - but don't tell her I said that), ya know?

Try checking your equations so they fit both Newton and Einstein (if you wanna) but in the meantime go easy on the old guy - I took physics in the 70's. Oh, click the 'spoiler' in my msg to 'you-know-who' earlier for a real wall-o-text.

~Granps

I haven't learned Einstein (in class) yet, but I know enough to understand what you're telling me is correct

[EDIT]Physics hasn't changed much since the 70s[/EDIT]

Spoiler!

(when you're little and people keep mentioning this Einstein you go searching for answers, some of it you retain... some you don't)

Oddly enough I have an easier time remembering theoretical things in written English rather than their mathematical counterpart. >_> why do you call me 'you know who' >_>

[Grandpa]

Your comments are welcome, I meant zero offense.
This whole conversation was 'carried away' by 'you-know-who' and me also, but for me it was fun.
My sis calls me "brat" to this day. She's pushing 60 (this June - but don't tell her I said that), ya know?

Try checking your equations so they fit both Newton and Einstein (if you wanna) but in the meantime go easy on the old guy - I took physics in the 70's. Oh, click the 'spoiler' in my msg to 'you-know-who' earlier for a real wall-o-text.

~Granps

I haven't learned Einstein (in class) yet, but I know enough to understand what you're telling me is correct

[EDIT]Physics hasn't changed much since the 70s[/EDIT]

Spoiler!

(when you're little and people keep mentioning this Einstein you go searching for answers, some of it you retain... some you don't)

Oddly enough I have an easier time remembering theoretical things in written English rather than their mathematical counterpart. >_> why do you call me 'you know who' >_>

Greetings Barotix, my friend

I didn't call you 'you-kno-who'...
The one I called 'you-kno-who' needs to remain nameless but his initials (and my spoiler) are under:
Ahhhh?? Kazaxat? Don't be too quick to laugh:
about 8 posts up
clicky that one...

It ain't physics that changed, it be my swiss cheese memory
Again, zero offense meant and certainly none to you - /salute!

[Grandpa]

v = dx/dt
a = dv/dt

When v is constant u can assum that v = d/t and when a is constant u can assum that a = v/t

u dont need to write that much, u'll get penalty point in exam.

Just explain as simple...

We agree, yes?

For Basic Algebra questions like this:
* A journey takes 6 hours if John travels 30km/h. How long will it take him if he travels at 45km/h ?
This (and questions like it) only need be solved for single variables.
One can rightly assume constant speeds and equal distances.

~GP