Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?
Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?NuclearNerd
Depends. Energy in minus energy out, regardless of inertial resistance.
As inertia is a resistance to change, I'd think, by definition, it would continue to move. From my understanding, though, inertia is not an independent variable, so the idea of increasing it without increasing mass doesn't make sense.
Oh wait... I think I've got you. Do you mean "Would increasing the mass of an object in motion, in such a way that wind resistance etc. is unaffected, increase or decrease its speed, taking into account momentum and friction?" In which case, I've got no idea.
Considering cars have engines and drivers the wind resistance would be counteracted and the brakes would not be engaged. If you mean something like a cart without a driver or any method of propulsion then it would still stop eventually however it would take longer than if it had a lower inertia (assuming it doesn't crash).
Inertia is a product of mass and velocity. You don't really increase something's inertia, you increase its speed, which results in an increase in inertia. If you did increase its speed, well, sure it would slow down. Air friction works no matter what speed you're going, and considering the tires would blow apart because they're not designed to deal with speeds exponentially higher than normal highway speeds, you'd have a lot of friction against the road, then the ditch next to the road, etc.
That's momentum, not inertia. Inertia, strictly speaking is not a quantifiable property in the sense that momentum is, but rather a reference to Newton's first law of motion. TC's question, since it involves a literally magical change in inertia, is difficult to answer in physics terms
Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?NuclearNerd
If you want good reading material on it, look up Newtons second law on wiki.
Inertia is an objects relationship between it's mass acceleration and related forces.
I don't really understand your question, air friction, or any sortof continual friction will eventually stop the car.
[QUOTE="NuclearNerd"]Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?CaveJohnson1
If you want good reading material on it, look up Newtons second law on wiki.
Inertia is an objects relationship between it's mass acceleration and related forces.
I don't really understand your question, air friction, or any sortof continual friction will eventually stop the car.
[QUOTE="NuclearNerd"]Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?Dawq902
If you want good reading material on it, look up Newtons second law on wiki.
Inertia is an objects relationship between it's mass acceleration and related forces.
I don't really understand your question, air friction, or any sortof continual friction will eventually stop the car.
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
CaveJohnson1
Hmmmm, bolded term doesn't make sense. Only thing that I could guess was that he was drawing the distinction between weight and mass, maybe?
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
xaos
Hmmmm, bolded term doesn't make sense. Only thing that I could guess was that he was drawing the distinction between weight and mass, maybe?lol, I don't know
Gravitational mass in classic physics is defined in the universal gravitational law. I think. I mess stuff up when translating from my own language.
Inertial mass is defined in Newton's Laws.
I just remember that the ratio of one's inertial mass to one's gravitational mass is postulated to be one, in some General Relativity lecture I participated (in which, again, gravitational mass is defined as the reason for the creation of a gravitational field, etc. etc.). So we don't really know if they are the same on every occassion.
[QUOTE="CaveJohnson1"]Hmmmm, underlined term doesn't make sense.
Nude_Dude
Gravitational mass in classic physics is defined in the universal gravitational law. I think. I mess stuff up when translating from my own language.
Inertial mass is defined in Newton's Laws.
I just remember that the ratio of one's inertial mass to one's gravitational mass is postulated to be one, in some General Relativity lecture I participated (in which, again, gravitational mass is defined as the reason for the creation of a gravitational field, etc. etc.). So we don't really know if they are the same on every occassion.
*This sounded better in my notes *
Eh, I've got a degree in engineering and I've never heard that term
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
CaveJohnson1
Hmmmm, bolded term doesn't make sense.It does make sense. Gravitational mass is defined as the ratio of the gravitational force on an object to the gravitational field strength; inertial mass is the ratio of the net force on an object to its acceleration. The two quantities of course seem to be equal in all cases, although the reason why is not clear.
Inertia-the resistance to change in motion or rest in relation to its mass and gravity. Now, lets say a car in motion was traveling at 80 mph. Lets say you were able to shazam magically change its inertia and increased it exponentially. Would the car continue to move because brakes and wind resistance can no longer stop it? Or would the car slow and stop because the wheels and engine can no longer move it?NuclearNerd
You don't increase or reduce inertia, even by magic, in the way you describe. The car already, in the absence of any friction, would continue moving at your chosen velocity indefinitely. I don't think you understand what inertia really means, and it seems the people in this thread don't either with the exception of xaos. A feather, a car, and a planet moving at the same velocity relative to some marker and to each other (ignoring how you accelerated them) slow according to friction, gravitational interactions, and other interactions with its environment. If you basically say that the body in motion is free from friction and interaction with space so that it doesn't lose energy to gravitational radiation, doesn't undergo radioactive decay etc... etc... that it's essentially in stasis... then they will ALL continue at the same velocity for as long as you maintain that suspension of other factors. It's meaningless to say that you increase a car's inertia in the manner you describe. The actual notion of inertia in the global sense is a resistance to change in momentum which is proportional to its mass, but it isn't mass... it isn't anything except... INERTIA. I'd normally assume you meant that you do those things I mentioned earlier, but you make it pretty clear with your talk of brakes and wind no longer being able to stop the car, that you think inertia is some lone variable you can increase on its own. You can't. You can increase mass, decrease friction, magically say you decouple the object from space so that it doesn't have to follow a geodesic that slams into the surface of the Earth... you can't just play with the concept: inertia. You're confusing issues like the old "F=ma" impulse question, and the variables involved with a concept that doesn't extend that far. I'm also a bit struck that you think increasing its Resistance to change in momentum would matter in relation to the engine or brakes. If you magically cause a car to move at a constant speed without requiring additional impulse, then the engine can be thrown out of the window. If you magically cause that same car to ignore friction, your brakes are likewise useless. You might as well ask what would happen if you poured a gallon of H2SO4 into a bucket of hope... it just doesn't work conceptually.
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
Hmmmm, bolded term doesn't make sense.It does make sense. Gravitational mass is defined as the ratio of the gravitational force on an object to the gravitational field strength; inertial mass is the ratio of the net force on an object to its acceleration. The two quantities of course seem to be equal in all cases, although the reason why is not clear. It's not unclear, it's a central assumption of GR, much as 'c' is an assumed and obserfved constant. Why 'c' isn't a number other than its observed and calculated value would seem to be much the same as asking why the proton's mass is what it is. These are constants of the universe, and without resorting to new theories or metaphysics, that's the best anyone gets as an answer.
(in all fairness, inertial and gravitational mass is not always one and the same)
Now I don't really know how you can 'change inertia', but assuming no other force comes to play, and friction continues to act on it, it will eventually stop. Increase inertia to a hypothetical infinity, and I assume it travels an infinite amount of length before stopping.
Changing the mass, however, is not really gonna cut it. If high school knowledge doesn't fail me, friction in a moving object is proportional to its' mass.
iamveryangry
Hmmmm, bolded term doesn't make sense.It does make sense. Gravitational mass is defined as the ratio of the gravitational force on an object to the gravitational field strength; inertial mass is the ratio of the net force on an object to its acceleration. The two quantities of course seem to be equal in all cases, although the reason why is not clear.This feels made up
[QUOTE="iamveryangry"][QUOTE="CaveJohnson1"]Hmmmm, bolded term doesn't make sense.
It does make sense. Gravitational mass is defined as the ratio of the gravitational force on an object to the gravitational field strength; inertial mass is the ratio of the net force on an object to its acceleration. The two quantities of course seem to be equal in all cases, although the reason why is not clear.This feels made up Much as I dislike coming to his defense, it isn't made up, it a nearly textbook answer.
You don't increase or reduce inertia, even by magic, in the way you describe. .Frame_Dragger
For the sake of the thought experiment, assume an increase in mass to obtain said increase in inertia. It basically becomes a very simple problem afterwards, regardless of how seemingly stupid the entire thing is.
You can't really change inertia. You can change the other factors that would affect inertia, but inertia isn't an independent variable that you can just dial up lol.
You could increase the mass of the car to increase the inertia, but it would still eventually stop because of friction and wind resistance.
You can't really change inertia. You can change the other factors that would affect inertia, but inertia isn't an independent variable that you can just dial up lol.
You could increase the mass of the car to increase the inertia, but it would still eventually stop because of friction and wind resistance.
Cheesehead9099
Even then, though, the mechanism by which the mass was added would affect the momentum and impulse of the starting mass
[QUOTE="xaos"]But the two statements are just two sloppy verbalizations of F = maCaveJohnson1
Gonna go with this, the way he worded it he made it sound like he was implying gravity had no units.I dunno why you'd think that. Is it because you associate 'ratio' with unitless quantities?
[QUOTE="Frame_Dragger"]You don't increase or reduce inertia, even by magic, in the way you describe. .coolbeans90
For the sake of the thought experiment, assume an increase in mass to obtain said increase in inertia. It basically becomes a very simple problem afterwords, regardless of how seemingly stupid the entire thing is.
DO IT FOR FUN
I know what you mean, but the OP was specific when referencing things like the ability of the engine or brakes to act on the moving body. Believe me, I'd love to play around with this for fun, but there just isn't a way. If the OP comes back and offers a question I can play with, I will, pinkie swear. ;) @xaos: F=ma defines the impulse needed to overcome (or not) the inertia of an object, which is related to its mass. The tendency of an object to resist a change in momentum however, if it carries momentum and can receive or impart an impulse, is a fundamental thing. F=ma is derived from the concept of inertia, but you can't reverse that when you're dealing with the fundamental concept. Remember... why mass has a tendency to resist a change in momentum is an ASSUMPTION which is used to formulate GR, that explains how mass interacts with space, and visa versa. Just as the invariance of 'c' provides the assumptive framework for Special Relativity, this is just "the way the universe is,' to simplify matters.
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