Letters and their meaning in physics equations

[Lisa Campbell]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

[Leyrann]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

The letters are everywhere on the planet the same. I think he just made a mistake and used s instead of v.

[Terez]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

The letters are everywhere on the planet the same. I think he just made a mistake and used s instead of v.

Don't you mean he used s instead of d?

[Leyrann]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

The letters are everywhere on the planet the same. I think he just made a mistake and used s instead of v.

Don't you mean he used s instead of d?

 

Yes. But then he just made a very weird mistake. I thought it could be explained because speed starts with s.

[Hybrid]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

The letters are everywhere on the planet the same. I think he just made a mistake and used s instead of v.

 

This is a little off-topic . . . but that's not true. I can't speak to language differences, but different letters are used by different disciplines to represent the same concepts.

[csarmi]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

 

I've got it from the standard physics denotation. (see any wiki)

 

s = distance, space (from 'spatium')

v = velocity (from velocitas)

t = time (from tempus)

 

Besides, s couldn't denote 'seconds' here. Second is a measurement unit, not a physical quantity.

 

(Some denote length by L and I've even seen 'D' used, but as far as I know, the std is 's')

[Leyrann]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

 

I've got it from the standard physics denotation. (see any wiki)

 

s = distance, space (from 'spatium')

v = velocity (from velocitas)

t = time (from tempus)

 

Besides, s couldn't denote 'seconds' here. Second is a measurement unit, not a physical quantity.

 

(Some denote length by L and I've even seen 'D' used, but as far as I know, the std is 's')

 

My Physics teacher has told me 1) that everyone on the planet uses the same letters, and 2) that the small s (so not S) is for second.

 

IIRC, distance has a D, but I can't be sure of that.

[smthappy]

the formula is S=V.t

 

And about the other powerful sa'angreal- it could be Tamirlin's ring.

[Hybrid]

csarmi, on 30 August 2011 - 08:22 AM, said:

 

Sharaman, your example is not very good. I can see what you're getting at, but the time to run 100m is not a linear function by nature.

 

s = v*t, or t = (s/v)

 

You may argue that v (your average speed) is linear (and distributed on a normal scale), but t could never be.

 

 

csami, I'm not quite sure where you got your formula from but from a physics point of view:

 

V (velocity or speed) = D (distance) / T (time)

 

which would give you:

 

T = D / V

 

I'm an Aussie so perhaps you have a different set of representative letters but it seems to me that your "s" represents seconds and if this is true, then your formula won't work. How can you work out the seconds it will take to run 100m when you need to know the answer (time) to be able to complete the formula?

 

 

I've got it from the standard physics denotation. (see any wiki)

 

s = distance, space (from 'spatium')

v = velocity (from velocitas)

t = time (from tempus)

 

Besides, s couldn't denote 'seconds' here. Second is a measurement unit, not a physical quantity.

 

(Some denote length by L and I've even seen 'D' used, but as far as I know, the std is 's')

 

My Physics teacher has told me 1) that everyone on the planet uses the same letters, and 2) that the small s (so not S) is for second.

 

Your physics teacher is wrong. (Lowercase s as an abbreviation for seconds is correct, however.)

[csarmi]

My Physics teacher has told me 1) that everyone on the planet uses the same letters, and 2) that the small s (so not S) is for second.

 

IIRC, distance has a D, but I can't be sure of that.

 

Your physics teacher is clearly mistaken.

 

First of all, people on the planet don't even use the same alphabet.

Second, things like this may and should change by country.

Third, these are only letters, afterall. What is important, is the meaning behind them.

Fourth, you seem to be mixing measure units and physical quantities (which I certainly hope your physics teacher wouldn't do). These are entirely different things. Surely they don't have to use the same 'letters'.

Fifth, science'w lingua franca is latin (and greek), hence the notations.

Sixth, there are more quantities than letters.

[Sharaman]

My Physics teacher has told me 1) that everyone on the planet uses the same letters, and 2) that the small s (so not S) is for second.

 

IIRC, distance has a D, but I can't be sure of that.

 

Your physics teacher is clearly mistaken.

 

First of all, people on the planet don't even use the same alphabet.

Second, things like this may and should change by country.

Third, these are only letters, afterall. What is important, is the meaning behind them.

Fourth, you seem to be mixing measure units and physical quantities (which I certainly hope your physics teacher wouldn't do). These are entirely different things. Surely they don't have to use the same 'letters'.

Fifth, science'w lingua franca is latin (and greek), hence the notations.

Sixth, there are more quantities than letters.

Seventh I wasn't talking about the laws of motion. I was talking about the frequency distribution of people who could run at various speeds, or lift weights, or sneeze in ascending decibels, or some other common physical feat.

[csarmi]

Well law of motion is a very common physical feat :)

 

And I wasn't talking about the law of motion myself either.

 

What I pointed out is that being able to run at a various speed (v) might follow a belle curve, but (s/v) wouldn't. I'm not sure what name that distribution has, if it has any. (dunno how the reciprocal of the Gauss-distribution is called).

 

But this got us very far.

[Leyrann]

Maybe it's better to start a new thread about this... It's clearly not simple anymore.

[yoniy0]

I've done that for you.

 

For what it's worth, I've mostly seen the letter 's' stand for displacement in physics, but this thread alone is proof enough the different people will use different notations.

 

EDIT: Oh, for those new to this thread, it used to be part of the 'ask a simple question...' thread in general WoT discussion.

[coolpool]

yoniy beat me to it but yeah, s stands for displacement, which is just the vector form of distance, which is the right letter to use in the equation above since velocity was used which is the vector form of speed...

 

vector just means it has a direction.. so displacement and distance are sorta the same things... except u can have minus for displacement as that indicates its gone backwards from the starting point whereas a distance is always positive; direction isn't taken into account for distance..

 

so wen its just scaler (the normal ones were used to) quanities... it wud be d=s*t were d is distance, s is speed (tho people do tend to use v anyway) and t is time

but wen vector qantities are used it is s=v*t where s is displacement, v is velocity and t is time.

 

 

What I pointed out is that being able to run at a various speed (v) might follow a belle curve, but (s/v) wouldn't. I'm not sure what name that distribution has, if it has any.

 

^^i get what u mean.. i think.. i think u've mixed ur statistic graphs up cos ur sorta saying that u think that the levels of the one power follow a culmative frequency graph (basically a streched out s shape like this > _.·´¯ so levels one and two are very simular power wise but as the levels increase, the gap between each lever increases so levels 12 and 13 have a large step between them and as the power levels reach the top, the difference between each level decrease so levels 22 to 23 are simular in power again like levels one and two were simular in power.. i understand totally what ur saying but i dont agree, i think it is a liner relationship but who knows..?

 

the multipul editing was for my awful spelling and for a bit more clarity like

[csarmi]

I've done that for you.

 

For what it's worth, I've mostly seen the letter 's' stand for displacement in physics, but this thread alone is proof enough the different people will use different notations.

 

EDIT: Oh, for those new to this thread, it used to be part of the 'ask a simple question...' thread in general WoT discussion.

 

Thanks yoniy :)

[FarShainMael]

Here is a wiki about the International System of Units, which defines for scientists throughout the world the basic units of various physical quantities. The table here shows the SI base units, which include length and time:

 

http://en.wikipedia.org/wiki/SI#Units

 

The unit symbols are defined - e.g. s for second - but 'typical' symbols for use of these things in equations are not, so physics teachers may use what they feel comfortable with.

 

I'm used to using t for time, s for distance, m for mass, u or v for velocity (as someone pointed out earlier, it's a vector), a for acceleration (also a vector). The symbol u is often used to denote an initial velocity, as in

 

v^2 = u^2 +2as

 

where ^ means 'to the power of'; thus u^2 means u squared.

 

(from http://en.wikipedia.org/wiki/Equations_of_motion#Classic_version )

[Red2111]

V (velocity or speed) = D (distance) / T (time)

 

this is the base equation froma mathematical point of view here in the States as well. T is general, i think when you imput the numbers you just cite which unit of measurement your dealing with, same as with D in terms of miles or kilomiters, cenemeters, meters, inches, ect

[drizzt_scimitar]

To throw in my personal experience, I usually see "x" to indicate displacement. And usually an initial anything (velocity, displacement, etc.) isn't given a new letter at all, but simply a subscript of the same one. For example, an initial velocity, with velocity denoted as "v", is often denoted "v_o".

 

I've also often seen the equation being discussed as "D=RT" (Distance=Rate*Time).

 

To be picky, though, the equation is really Velocity_average=(Location_final-Location_initial)/(Time_final-Time_initial).

 

To find velocity at a specific point in time, or instantaneous velocity, you use the fact that velocity is the time derivative of position, or v=dx/dt