Quote from Vain :

sqrt(1g²+0,5g²) = 1.12g

That is wrong.

there is no 1g downwards.

you are not accelerating downwards.

you are only accelerating forward.

there is only 0.5g forward.

this is getting silly, stop it

Now, when you are made to believe that you are accelerated sideways while actually not being I tend to say that this acceleration is being simulated.

And by the way: For better understanding you can also use the definition of acceleration as being Force per mass. This definition requires no movement and is better suited here.
Defining acceleration as the change of velocity is only valid in free space. So rethink your point of view.

Vain

let us accept for a moment that that formula is correct and that it is correct for the case where you are in a car accelerating forward.
v/ (1g^2 + .5g^2)

let us consider a second case

how would you describe the acceleration experienced by someone FALLING from the sky and at the same time being propelled FORWARD by a small engine he is carrying?

+-->
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v

Quote from Vain :

And by the way: For better understanding you can also use the definition of acceleration as being Force per mass. This definition requires no movement and is better suited here.
Defining acceleration as the change of velocity is only valid in free space. So rethink your point of view.

Vain

You obviously never took proper physics lessons.
I am not going to continue this pointless discussion.

I don't see what you're missing from this discussion George. Perhaps physics isn't for you

Lets simplify this.

When you are in a REAL car and accelerate at 1G forwards, the combined accelerations acting on you are gravity (which is an acceleration NOT a force, but CAUSES a force) you experience 1g long and 1g vertically = 1.414g combined at an angle of 45 degrees.

In the Force Dynamics, to simulate that, the car will tip you over at about 50 degrees (if the motion range was sufficient and you'd feel the effects of 1g, which is the most you can 'harness' without actually moving. This tricks your body and your inner ear into believing what you can see on the monitor in front you. It doesn't tip you at 45 degree's because it tries to exaggerate the acceleration force so it stands out more, making you beleive you got more value for your money

Rather than bursting into tears because w don't get what you're trying to say, why don't you reason your arguments a touch better. As far as I can see all you're saying over and over that gravity isn't an acceleration, and it is. If you are so clever and all knowing about physics you'll be able to explain to us properly and without doubt where all of us are going wrong.

acceleration does not cause a force.

What "acceleration" is and what causes it, is a long discussion. Same with "force" and "velocity". i am not here to teach you elementary mechanics.

go read a book. kittel/knight mechanics is a good start (the one they teach at Berkeley). it will(hopefuly) give you all the definitions you need.

i've got a scholarship at my university, where i study physics. i ranked 3rd in the entering examinations. telling me that physics isn't for me is preposterous.

the argument "my IQ is such high therefore i must be right and you are wrong" is the weakest argument of it all.

i really would like to get a real explaination, why a _simulator_ like force dynamics can not work.

i honestly think it is the best way to do it. enlighten me .

the FORCE that exists between MASSES is called "GRAVITY".

GRAVITY is a FORCE

GRAVITY is not CAUSED by ANYTHING, but by the EXISTENCE of MASS.

you have mass here and mass there and there is GRAVITATIONAL PULL between the two.
WHY, WE DO NOT KNOW.

when you are SITTING on your ASS, the earth PULLS YOU DOWNWARDS.
it exerts a FORCE on you.
the CHAIR on which you SIT exerts an OPPOSITE FORCE on you and thus you STAY STILL.

THE NET SUM OF THE FORCES YOU FEEL IS ZERO
NADA
ZIP
NULL
0

you are NOT ACCELERATING.
you are NOT MOVING. (relative to ground)
you are NOT EXPERIENCING ACCELERATION.
your VELOCITY IS VECTOR 0
your ACCELERATION is ZERO
a=f/m =0 since f_total on you is ZERO. if you consider only the gravitational pull, yes, a=1g but that is WRONG because there is also the force from the CHAIR. otherwise if you write a=1g that means you are accelerating towards the GROUND, THROUGH the chair INTO the ground.

He who knows not, and knows not that he knows not, is a fool - shun him.
He who knows not, and knows that he knows not, is a child - teach him.
He who knows, and knows not that he knows, is asleep - wake him.
He who knows, and knows that he knows, is a wise man - follow him.

Yes, we all know you're not ACTUALLY accelerating when you sit on a chair. Geez, you need to lighten up. You just don't get the whole point of this discussion do you, and how moving you around and make you feel an acceleration and the resulting force can trick your mind.

Do not apply for a job at Force Dynamics.

Also shouting just makes you look more like a fool (see my previous post)

now, you are in a CAR.

you step on the GAS.

there is TORQUE applied on the WHEELS and the car starts MOVING FORWARD.

until now you were SITTING IN A CHAIR. you were NOT MOVING. you were NOT ACCELERATING. you were STILL.

but now you ACCELERATE FORWARD.

but NOT BECAUSE OF GRAVITY. NO.

the CAR moves FORWARD. the CHAIR which is part of the CAR, PUSHES you FORWARD.

it ACTS a FORCE on your BACK. you FEEL the PRESSURE.
the FORCE is CONSTANTLY on your BACK.
there is NO force to COUNTER that force so you are ACCELERATING FORWARD.

Golly gosh. Yes yes, we know. Can you go now? I know gravity doesn't make a car move down the road...

*sings a nice song to shut him up*

Edit: And please stop shouting (capitals). You make yourself look like a fool. In fact I'd say you were 9 and have just done 'basic physics and shouting for beginners' class with your posting style.

but do we as humans really feel the accelaration or the force that produces the acceleration? i tought it's more about the forces that effect us and in that matter _force_ dynamics is quiet right with their idea, or not?

I am not SHOUTING, i am putting EMPHASIS. i could use underline but i am BORED and CAPS LOCK is EASIER.

and, in my book, whoever uses these smartass sayings (he who knows etcetcetc) instead of knowledge, is not a knowledgable person.

No, I was just stressing my opinion that a) your level of physics isn't actually that high. Certainly not much above mine in this topic area and b) you ar acting like a fool.

I don't think you know, but you think you know when perhaps you know not and thus you are fall into the former category above. It's a put down. It's a subtle way of saying you're not worth listening to in that mood. Calm down, have a cup of cocoa and come back in a bit when you've calmed down. Perhaps browse our excellent range of threads, including some fine ones on smoking and car crashes.

Also, there is a great thread on RSC about rFactors physics and gravity. You seem like just the right person to go an annoy them over there. *points*

Quote from Fetzo :

i really would like to get a real explaination, why a _simulator_ like force dynamics can not work. .

Define "work".

Make you feel like you are actually in a car and stepping on the gas? no.
Make you feel bumps on the road? yes.
make you feel lateral acceleration? only for a very short duration. very short. and limited as to how often the same turns (right and right and again right) can be taken.

depending on what you mean by "work" the answer varies from "perfectly" to "not at all"

Quote from tristancliffe :

No, I was just stressing my opinion that a) your level of physics isn't actually that high. Certainly not much above mine in this topic area and b) you ar acting like a fool.

my knowledge of physics is on a level that only my professors can judge. not you. not because you are not clever or able, but judgement comes from someone with greater knowledge.
i am using caps because i see ignorance and unwillingness to accept said ignorance. i tried to give emphasis on certain words.

you said some pretty silly things back there (that gravity is not a force but an acceleration and that it causes a force... wtf?). maybe because you engineers learn these things at a more practical level ignoring the more fine details about definitions and importance of terms.
i do not know how to make you know more. go read a book that talks about rigorous definitions and the importance of knowing what causes what to happen.

I just wanted to say that if you "Lay on your back with your feet straight up in the air" you feel the exactly same force in your back as you do as you are accelerating at 9.81m/s2 in space. But to get such a smooth acceleration...

F = m * a

If m = 100kg and F = 981 N -> g = 9.81m/s2 even if not moving.

:munching_

But gravity isn't, as far as humans know, a force. It is an acceleration. If it were a force a kg of gold and a tonne of gold would fall at the same speed. But as it's an acceleration the force exerted on a body is inversely proportional to said bodies mass.

Since Newton's "Principia Mathematica" it has been known that gravity, wherever it occurs, is an acceleration that imparts force rather than a force that imparts an acceleration.

Quote from george_tsiros :

Define "work".

Make you feel like you are actually in a car and stepping on the gas? no.
Make you feel bumps on the road? yes.
make you feel lateral acceleration? only for a very short duration. very short. and limited as to how often the same turns (right and right and again right) can be taken.

depending on what you mean by "work" the answer varies from "perfectly" to "not at all"

Yes well if we are to get the exact feel we all know we need to jump in a real car and go around a real track thats very obviously not the aim of a motion simulator A motion simulator is just a device to enable you to be more fully immersed in a simulation that involves motion it's aim is not to replicate the said motion

Gravity is a force of attracti ... n bodies that have mass.

Quote :

If it were a force a kg of gold and a tonne of gold would fall at the same speed.

They do.

Quote :

force exerted on a body is inversely proportional to said bodies mass

no.
F= G * Mearth * Myou /r^2

Gravitational pull is LINEARLY proportional to BOTH masses.
but because there is also INERTIA in the way, which acts ALSO linearly with mass (mass is the measure of inertia), all masses accelerate towards the earth with the SAME acceleration (friction due to air notwithstanding)

:doh: That was a silly mistake. I know 1kg will fall the same speed as 1 tonne, and I have no idea why I typed that.

I meant to say that if it were a force then the acceleration of 1kg of gold would be less than 1 tonne of gold while freefalling and discounting air resistance. Thats better. Cos they don't accelerate at different rates do they

I was just trying to explain in basic way that if a person weighs 100kg and a force of 981 N is measured (using some kinf of scale), the acceleration is 9.81m/s. In moon it's less and in sun it's more.

It all comes to the fact of newton's laws

Though this wasn't supposed to be a physics discussion (?) so all this debating about off topic isn't really...going anywhere



EDIT: edited

aren't the forces in the force dynamics quiet similar (they aren't obviously not as strong) like the forces affecting us in a real car? aren't the forces we experiencing the values the matter (the we really can feel)?

we aren't really noticing acceleration in a sealed car, do we?

Quote from tristancliffe :

:doh: That was a silly mistake. I know 1kg will fall the same speed as 1 tonne, and I have no idea why I typed that.

I meant to say that if it were a force then the acceleration of 1kg of gold would be less than 1 tonne of gold while freefalling and discounting air resistance. Thats better. Cos they don't accelerate at different rates do they

for fscks sake tristan, READ