Originally posted by joe shmo It does, when a bullet is fired every thing else in the system moves. Fire a bullet to the right, the universe moves to the left. Its consevation of momentum.
No, conservation of momentum shows itself in the recoil of the firearm.
Anyway, momentum and energy are two different things.
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22 Jan '10 04:43>1 edit
Originally posted by AThousandYoung No, conservation of momentum shows itself in the recoil of the firearm.
Anyway, momentum and energy are two different things.
Which in turn,imparts momentum on the person, who imparts momentum on the earth, which changes the momentum of the solar system,galaxy,ect..........Im not wrong.
Originally posted by joe shmo Which in turn,imparts momentum on the person, who imparts momentum on the earth, which changes the momentum of the solar system,galaxy,ect..........Im not wrong.
Thats quite correct Joe, I had never considered that the firing of the gun would impart a force (albeit miniscule) on the sun but as you point out it does!
We always consider Conservation of Momentum within a 'system' but that 'system' (thanks to gravity) is the Universe.
Or is it? Is there a minimum force (ie a quanta of force)???????????
Momentum and energy are not the same thing guys...I was talking about energy.
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23 Jan '10 13:36>
Originally posted by wolfgang59 Thats quite correct Joe, I had never considered that the firing of the gun would impart a force (albeit miniscule) on the sun but as you point out it does!
We always consider Conservation of Momentum within a 'system' but that 'system' (thanks to gravity) is the Universe.
Or is it? Is there a minimum force (ie a quanta of force)???????????
Now this I no almost nothing about, But what about weak nuclear force is that a quanta of force,or is this actually a strong force in comparison to what we are talking about?
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23 Jan '10 13:51>1 edit
Originally posted by AThousandYoung Momentum and energy are not the same thing guys...I was talking about energy.
They arent the same, but the are both conservation laws and they are related
Ke = 1/2*m*v^2 (Kinetic Energy)
dKe/dv = m*v ( momentum, the rate of change of Kinetic energy with respect to velocity)
dKe/dt = m*v*dv/dt = m*v*a = P (Power, the rate of change in Kinetic energy with respect to time)
Originally posted by joe shmo They arent the same, but the are both conservation laws and they are related
Ke = 1/2*m*v^2 (Kinetic Energy)
dKe/dv = m*v ( momentum, the rate of change of Kinetic energy with respect to velocity)
dKe/dt = m*v*dv/dt = m*v*a = P (Power, the rate of change in Kinetic energy with respect to time)
Is there any difference between a Kg of aluminum going 100 Km/hr V a kg of Uranium going 100 Km/hr? It would seem at least the uranium would have more penetrating power as in its use in military ordinance. Is that all there is to it, the mass alone? What about for instance, a billiards ball of standard material V one made of say standard on the outside but lead on the inside, I guess that would be biased because you couldn't make them the same size unless there was a hollow in the lead ball. So what about that, a specialized billiard ball with ordinary stuff on the outer few millimeters and a lead foam inside so they weigh the same, any difference in the kinetics?
So I googled 'Momentum Vs Kinetic energy' and found this great link with nice thought experiments to explain the difference:
Originally posted by sonhouse Is there any difference between a Kg of aluminum going 100 Km/hr V a kg of Uranium going 100 Km/hr? It would seem at least the uranium would have more penetrating power as in its use in military ordinance. Is that all there is to it, the mass alone? What about for instance, a billiards ball of standard material V one made of say standard on the outside but ...[text shortened]... erence:
Originally posted by sonhouse Is there any difference between a Kg of aluminum going 100 Km/hr V a kg of Uranium going 100 Km/hr? It would seem at least the uranium would have more penetrating power as in its use in military ordinance. Is that all there is to it, the mass alone? What about for instance, a billiards ball of standard material V one made of say standard on the outside but ...[text shortened]... erence:
They'd have the same energy but the aluminum projectile would be bigger. This means more air resistance, vulnerability to wind, and probably a greater cross section spreading the force over a larger area of armor.
You're referring to density.
So what about that, a specialized billiard ball with ordinary stuff on the outer few millimeters and a lead foam inside so they weigh the same, any difference in the kinetics?
Possibly. It would depend on weight distribution inside the ball and hardness of the ball. Also there's the possibility of deformation; this might be part of "hardness". If those were also the same it should act the same.