If a stone hits a glass does the breaking of the latter depend on energy of the stone or the momentum ?

Answer 1

EDIT-Rick B, i disagree, if it's force that's important, then impulse wouldn't tell you how much force there was, the smaller stone could apply more force over less time, and still have a smaller impulse. Surely a smaller stone (with less momentum but more speed and energy) *would* be expected to decelerate more rapidly? I'd have thought it had more to do with the way the glass deals with the kinnetic energy, and whether its able to dissapate it sufficiently.

Besides, force on its own doesn't necesarily mean much. Applied correctly, a massive force could be applied to the glass, and it wouldn't shatter, it would just be accelerated.--EDIT END

Well, if its a particular stone, then it doesn't matter too much, you can't change the momentum without changing the energy, for any given energy, you can calculate the momentum exactly.

But if you've got a smaller stone and a larger stone traveling with the same momentum then the smaller stone would have more energy.

{......E = 1/2 x m x v x v
.......p = m x v
.......If you halved m, and doubled v, you have a smaller stone traveling twice as fast. momentum would be unchanged, but energy would have to be doubled}

More to the point, you could have a big stone traveling with more momentum than a smaller one, but the smaller one having more energy.

The physics of whether something would break are actually pretty complicated, i certainly don't know them. It could probably depend on a lot of things, like the angle you hit the glass at, and it could be different for different materials in the glass.

But generally, in basic terms, it's the energy thats important, because it takes a certain ammount of energy to break the *chemical* bonds holding the mollecules in the glass together.

I'm 95% sure on that....

Answer 2

I would say, the momentum.

The question of whether the glass will break, probably depends on the amount of force exerted on the glass, and the time period over which that force is exerted. The product of these two (F·t) is called "impulse"; and it also happens to equal the change in momentum of the rock as it hits the glass.

So, let's say there is a certain minimum impulse, I_min, which is required for breakage. If I_min exceeds the momentum of the rock, then the rock cannot break the glass (because the rock will exhaust all of its momentum (will slow to a stop) before it's able to deliver impulse I_min). But if the rock's momentum exceeds I_min, it will be able to break the glass.

Answer 3

It only depends upon the momentum i.e., the mass and velocity of the stone and the impulse occured due to the stone after hitting the glass.

Answer 4

Energy = 1/2 m.v^2 and Momentum = m.v where m is the mass and v is the velocity. Thus both are related. And breaking of glass depends on the ability to absorb the moementum or fracture toughness. Normal glass breaks easily and toughened glass can withstand some impact.

Answer 5

Momentum is the rate kinetic energy changes in relation to velocity. Kinetic energy is what is difused in to the glass. The bonds that hold the glass molecules break as the waves of kinetic energy diffuses in to the glass.

Answer 6

it's impact.