What do you mean?
What do you mean?
Yeah, seen that all before. Which bit are you picking up on now? That I'm saying G isn't a force? Well it isn't. Yes, you can derive the force from the acceleration, in much the same way that I can speed=distance/time. Just because I know the distance travelled doesn't make distance a speed.
Gravity is an acceleration, NOT a force. I'd have thought you'd have known that.
Gravity is an acceleration, NOT a force. I'd have thought you'd have known that.
Uhm, you're repeating the exact same thing here Tristan. Wrong again.
I have you in high regard, but you're kinda goofing up here
Edit: To sum up: gravity is a force per unit of weight. Thus, 1kg has 9,81 N working on it while 1000kg has 9810N working on it. As you said, this results in the exact same acceleration of 9,81 m/s/s.
Let's just all agree on this one shall we? -> F=m*a
Edit2: I suggest you open a physics book or ask a prof, tristan. Gravity is a force. Acceleration only happens when nothing is countering it (i.e. when something's in the air).
Yes the forces are similar enough to make us believe the computer simulation is real - and that is enough
But it by no means simulates all the forces well. Just as the computer simulation itself cannot simulate all aspects, we just don't have enough PC on our desktops.Heh, last 3 pages contain nothing about traction control nor ABS 
About human inner ear and acceleration: http://www.hhmi.org/cgi-bin/as ... uroscience%2Fans_005.html
About human inner ear and acceleration: http://www.hhmi.org/cgi-bin/as ... uroscience%2Fans_005.html
What came first the chicken or the egg
Not it's not the same thing.
Originally I stated (by mistake) that two objects of dissimilar mass would fall at the same rate if gravity was a force. But in fact if gravity was a force then the lower mass would fall slower.
Acceleration of a kg when imparted with a constant force is less than the acceleration of a tonne when imparted by the same force. So bigger objects would fall faster. But as gravity is an acceleration (caused by, we believe, the warping of spacetime by the presence of masses) the bodies actually fall at the same rate, and feel a different force. As the force is different in the same gravitation conditions then gravity must be an acceleration and not a force.
I just got muddled somehow in the first post prior to my :doh:.
B2B - the egg, and I know a joke to prove it But just because you can find one thing from something doesn't make that something the same as the other. Just because you can easily find the force acting on a body due to gravity doesn't make gravity a force.
Gravity is a constant right? It's the same all over the surface of the earth, so constant in that regard, not constant universally. So if gravity was a force, then every object would feel the same force no matter what it's mass is. But it isn't a force, it's an acceleration, and thus different masses 'feel' a different force.
Edit again: I know that gravity can be considered a 'force per unit weight', which is the same thing as an acceleration just written differently. Like speed can be written as 'change in distance per unit time'. That doesn't make speed a distance or a time, just like gravity isn't a force or a mass.
Obviously our understands are, in effect, the same, but George is completely missing the point we were trying to make, and totally fails to see why explaination. Not because he's wrong, but because he's been taught differently I suppose. We all know how bodies react to gravity, and how the forces resolve from gravities attraction, but still I maintain that does not make gravity a force but an acceleration. When you express gravity you write x m/s/s. Never ever do you write x N, because that's not valid.
Btw, I've given up writing millions of posts, so I am just going to edit this one. If you don't see it and think I've run away then you're mistaken. And at the end of day I maintain that the force dynamics seat could, if it could tip you up vertically, provide you with the sensation of 1G acceleration longitudinally, or laterally if it was tipped 90 degrees to the side. Greater accelerations can only occur through the movement of the rig throughout it's range, so a peak of 4 or 5G might be possible for a fraction of time, with 1G sustained in any direction. And even then the force acting on your back as you accelerate is wrong, because the seat moves away from you rather than presses into you, but it's sufficient to trick you into believing.
Originally I stated (by mistake) that two objects of dissimilar mass would fall at the same rate if gravity was a force. But in fact if gravity was a force then the lower mass would fall slower.
Acceleration of a kg when imparted with a constant force is less than the acceleration of a tonne when imparted by the same force. So bigger objects would fall faster. But as gravity is an acceleration (caused by, we believe, the warping of spacetime by the presence of masses) the bodies actually fall at the same rate, and feel a different force. As the force is different in the same gravitation conditions then gravity must be an acceleration and not a force.
I just got muddled somehow in the first post prior to my :doh:.
B2B - the egg, and I know a joke to prove it
But just because you can find one thing from something doesn't make that something the same as the other. Just because you can easily find the force acting on a body due to gravity doesn't make gravity a force.Gravity is a constant right? It's the same all over the surface of the earth, so constant in that regard, not constant universally. So if gravity was a force, then every object would feel the same force no matter what it's mass is. But it isn't a force, it's an acceleration, and thus different masses 'feel' a different force.
Edit again: I know that gravity can be considered a 'force per unit weight', which is the same thing as an acceleration just written differently. Like speed can be written as 'change in distance per unit time'. That doesn't make speed a distance or a time, just like gravity isn't a force or a mass.
Obviously our understands are, in effect, the same, but George is completely missing the point we were trying to make, and totally fails to see why explaination. Not because he's wrong, but because he's been taught differently I suppose. We all know how bodies react to gravity, and how the forces resolve from gravities attraction, but still I maintain that does not make gravity a force but an acceleration. When you express gravity you write x m/s/s. Never ever do you write x N, because that's not valid.
Btw, I've given up writing millions of posts, so I am just going to edit this one. If you don't see it and think I've run away then you're mistaken. And at the end of day I maintain that the force dynamics seat could, if it could tip you up vertically, provide you with the sensation of 1G acceleration longitudinally, or laterally if it was tipped 90 degrees to the side. Greater accelerations can only occur through the movement of the rig throughout it's range, so a peak of 4 or 5G might be possible for a fraction of time, with 1G sustained in any direction. And even then the force acting on your back as you accelerate is wrong, because the seat moves away from you rather than presses into you, but it's sufficient to trick you into believing.
THANK YOU GOD IN HEAVEN, THANK YOU!
it means that my english skills are definately not good enough for this discussion :P.
i think B2B@300 understood what i meant.
what i wanted to say: if we had no windows in our car and would have a constant acceleration of 1 g we wouldn't notice a difference from lying on the floor.
but i guess you already gave that example :P.
i am confused now and stick to reading this stuff
.Well, you'll never feel the forces of the real thing in a force dynamics because in reality you always have 1G pulling you downwards (disregarding bumps/crests) and the accelleration forces added to that (as tristan already said). In the force dynamics as soon as you simulate any accelleration force (tilting the seat backwards) the force pulling "down" decreases as it's used for pulling "back" now.
But I really doubt there's any difference between sitting in a seat lying on the back on earth and being accellerated forward with 1G in a seat in space.
But I really doubt there's any difference between sitting in a seat lying on the back on earth and being accellerated forward with 1G in a seat in space.
yes there will be.
if you are on a shuttle, your back turned towards the ground, and the shuttle accelerates upwards, you would feel as if your body weighs twice as much.
if you are on a shuttle, your back turned towards the ground, and the shuttle accelerates upwards, you would feel as if your body weighs twice as much.
if you mean 1g forward, then yes you would very very well tell the difference even if you were deaf AND blind.
@android
yes that's right. because the sum of the forces you are experiencing in a force-dynamics seat cannot exceed the 1G + some forces from rotation movements. yep i get that.
thats why i said "they are similar" but "not as strong". in fact accelerating in a force-dynamics must feel like accelerating over a hill or something similar because you are lift off your seat. there is definately some force missing there.
@george:
got it.
yes that's right. because the sum of the forces you are experiencing in a force-dynamics seat cannot exceed the 1G + some forces from rotation movements. yep i get that.
thats why i said "they are similar" but "not as strong". in fact accelerating in a force-dynamics must feel like accelerating over a hill or something similar because you are lift off your seat. there is definately some force missing there.
@george:
got it.
Well, I just finished an introductory Dynamics course here at the university, people here made the same logic error.
There is some. The 9,81m/s/s acceleration would require a 9,81m force to be applied to you by the seat. The same force the ground here on Earth applies to you. This principle is why wheeled space-stations such as in 2001 can have artificial gravity.
Edit: Dang! I think this thread is setting a new record for posts per hour!
Just wait till you get to rigid body mechanics... and the strobe... kekekeke PWNT
what do you study?
dammit, i need sleep
It included rigid body dynamics (up to a point, of course). The course was preceded by a courses in statics and calculating stress, strain and deflection of materials and stuff.
I study Industrial Design Engineering at the Delft University of Technology. Not much of a technical study, though. Just enough to get some respect from actual engineers
(with emphasis on some).
I study Industrial Design Engineering at the Delft University of Technology. Not much of a technical study, though. Just enough to get some respect from actual engineers
(with emphasis on some).Also doesn't the force of attraction between two objects have something to do with the masses of both objects? All objects have mass and therefore have a "gravitational force" albiet small in relation to the earths, but that would explain the difference in force produced by different wieght objects no?
Two magnets attract, how are they attracted? By a force or an acceleration?
just pondering, ignor me
Two magnets attract, how are they attracted? By a force or an acceleration?
just pondering, ignor me despite the facts figured out in this thread, i am sure the force dynamics produces a great feel of immersion. maybe the first minutes will feel a little odd, but i think the driver will adjust.
i drove the big outrun arcade when i was ten and i thought i would nearly fall out of the machine in fast corners. i think human senses can be tricked very easily :P.
i drove the big outrun arcade when i was ten and i thought i would nearly fall out of the machine in fast corners
. i think human senses can be tricked very easily :P.Thats why I said in space, and not on earth. Also, since when do cars accellerate upwards?
can't quite agree with you there: you're right in the point, that you won't feel to much accelaration, but a force (grav. Force). They use it to make you believe you feel accelaration, just like in a real car, where i don't think you feel the accelaration but instead the resulting force.
so the chair should actually work.
Hmn could it be that in LFS the rotational force of the motor reving is too strong, which then causes the cars to spin? Do they always spin in the same direction when trying to take off on a flat smooth surface?Reading through this thread.
Because of the engine's torque, one tire will get more downforce than the other. Viewed from the rear, most engines rotate counter-clockwise, with the resulting torque creating a bit more downforce on the left rear, which causes a slight yaw to the right. However since both tires are spinning fast, grip and forces are low, and it's not very much of a yaw. (LFS yaws the cars left). Do a websearch for "burnout contest videos" and you'll see some good examples of control with both rear tires spinning at high speed. LFS doesn't model this.
Gravity is a field. The amount of force it generates on an object is proportional to the mass of the object, so the rate of acceleration for an object of any mass is the same if no other forces like aerodynamics are involved.
Good grief, this thread went crazy.
My point was that you can not tell the difference between these two situations:
1) Stuck in a box strapped to a chair tilted back 90 degrees.
2) Being in 0 gravity while accelerating forward at 9.81 m/s^2.
Is gravity a force or acceleration? In the context of this discussion, who cares? The point is you can't discern between acceleration from being pinned to the Earth from an actual, literal acceleration in a direction straight "up." I think they taught us that in 9th grade. Enjoy your university studies
If you tilt the chair back 45 degrees you feel exactly the same as you would if you were horizontal in a gravity field of 70% Earth's strength while accelerating forward at 70% of 9.81 m/s^2. My point was you do not need movement to feel as though you are accelerating. You just need to be pressed up against some huge thing like the Earth to feel it.
And no, lying on your back with your feet straight up in the air will not feel like you're in a car accelerating at 1g because the "downward" component of the acceleration is now gone. I didn't say you would. However, you most certainly do feel exactly an acceleration of 1g "forward" in that you are facing upwards. You are not moving in this situation. Therefore, you do not require movement (an "actual" acceleration) to feel acceleration.
I can't believe I'm having this discussion and that point is being totally missed by someone so educated in physics.
My point was that you can not tell the difference between these two situations:
1) Stuck in a box strapped to a chair tilted back 90 degrees.
2) Being in 0 gravity while accelerating forward at 9.81 m/s^2.
Is gravity a force or acceleration? In the context of this discussion, who cares?
The point is you can't discern between acceleration from being pinned to the Earth from an actual, literal acceleration in a direction straight "up." I think they taught us that in 9th grade. Enjoy your university studies If you tilt the chair back 45 degrees you feel exactly the same as you would if you were horizontal in a gravity field of 70% Earth's strength while accelerating forward at 70% of 9.81 m/s^2. My point was you do not need movement to feel as though you are accelerating. You just need to be pressed up against some huge thing like the Earth to feel it.
And no, lying on your back with your feet straight up in the air will not feel like you're in a car accelerating at 1g because the "downward" component of the acceleration is now gone. I didn't say you would. However, you most certainly do feel exactly an acceleration of 1g "forward" in that you are facing upwards. You are not moving in this situation. Therefore, you do not require movement (an "actual" acceleration) to feel acceleration.
I can't believe I'm having this discussion and that point is being totally missed by someone so educated in physics.
Traction Control and Anti-Lock Brakes
(218 posts, started )
FGED GREDG RDFGDR GSFDG