An Object That Has More Inertia Compared To Its Weight

[DJEN]

You see, I've been wondering about how an object with more inertia compared to its weight would act. If any of you physics peopls would reply and not ramble all over the place, I would be very glad.

[magnemoe]

Its easy to predict, it would weight less but would still require the same force to accelerate.

More fun it would behave as it would in less gravity Say inertia is 60 kg but weight is 20, it would then handle just as an 60kg mass on mars where the gravity is 1/3 of earth.

[MockKnizzle]

In more precise terms, you're asking about what would happen if inertial mass (the mass used in F=ma) and gravitational mass (used in F=G*m1m2/r^2) of an object weren't the same, meaning that the object would be violating the Equivalence principle.

My initial thought is that you could just think of it as applying a correction to the mass in question when calculating gravitational forces, in this case multiplying the object's mass by some fractional amount. The general effect would be just as magnemoe described, essentially the object would behave on earth as it would in a weaker gravitational field.

Now, if this effect is extended to more than just one object, there might be some paradigm-shifting cosmological problems that physicists would need to work out, but I'm certainly not knowledgeable enough to speculate on what those might be.

[cantab]

Such an object basically exists - a helium balloon! The weight, if you want to be technical the net weight, is less than would be expected from the total mass, indeed it's often negative.

Of course the behaviour of a balloon is quite strongly influenced by fluid dynamics. That's necessarily going to be an issue with anything buoyant.

[GoSlash27]

http://www.youtube.com/watch?v=l2VuosSk9zU

Same mass, lower inertia due to a reduced mass distribution.

Best,
-Slashy

[Idobox]

Such an object basically exists - a helium balloon! The weight, if you want to be technical the net weight, is less than would be expected from the total mass, indeed it's often negative.

Of course the behaviour of a balloon is quite strongly influenced by fluid dynamics. That's necessarily going to be an issue with anything buoyant.

You can have plenty other examples, like stuff in water, or magnetic levitation, or simply hanging to a spring...

In particular, there are a number of industrial applications where stuff is hanging from a moving support, significantly reducing its apparent weight, but not its mass, and it's quite weird to move them around at first.