Does a RB travel with constant rotation, or accelerate?

[Marinekayak]

I'm surprised no one has asked what hits the ground first a fired bullet or a dropped bullet.
And its a good thing we don't have to worry about Coriolis effect at the ranges we are shooting at.

 

[Griz44Mag]

I'm surprised no one has asked what hits the ground first a fired bullet or a dropped bullet.
And its a good thing we don't have to worry about Coriolis effect at the ranges we are shooting at.

When I drop something it must never hit the ground because I can never seem to find it!
(The correct answer is neither - and both....

 

[tenngun]

When I drop something it must never hit the ground because I can never seem to find it!
(The correct answer is neither - and both....

Falling objects have their own physics unrelated to normal space time three dimensional universe.
A liquid or piece of dirt can fall in a straight line, turn 90 degrees and travel sideways to get in your eye.
Should you drop a piece of a lock. It goes forward in time to a point where it can only be found by replacing the part.
Flys are an exception. Fly disappear in to a black hole if dropped and are never seen again

 

[hawkeye2]

Thanks for the explication. I had never realized small parts could travel in time though I knew that the surest way to find them was to buy 2 replacements.

 

[TNGhost]

I still want to know if you fire a ball straight up, is it still spinning as it hits the ground?

If so, is it spinning in the same direction as on the way up?

 

[bisleyjohn]

Yall're forgetting that round ball are metallic and that considering any rotating conductor passing through a magnetic field can induce a torquing elctromagnetic effect upon a ferritic icebox handle, producing cold suds.

 

[tenngun]

I still want to know if you fire a ball straight up, is it still spinning as it hits the ground?

If so, is it spinning in the same direction as on the way up?

Got me.
Should it spin at the same or near the same RPM it should still be spinning when it reaches the top of its arc. As it starts to fall it would then keep its same rotational speed.and should hit the ground at near the rpm and in the same direction it had when it was fired
Gut feeling is it will slow, and it should slow to near stop at the top of the arc. And tumble on the way down since there would be little or no stabilization.
But the weight of the spru May cause it to turn over. Although the spinning should resist turning so a spinning ball should come down in the same alignment
Aaaagggghhhhh.

 

[hawkeye2]

Spinning, tumbling, stabilized or not, my thoughts are it doesn't matter at all since gravity and the wind are the forces acting on it and we aren't trying for the 10X ring of a target laying flat on the ground. Edit; everybody ought to be running for cover at this point anyway.

If it was fired straight up like inside a piece of pipe it should land the same way it was loaded like sprue up. Would it land back on the muzzle? If it were fired without a guide your guess would be as good as mine. It would be nearly impossible to fire it exactly straight up and even if it were the wind would carry it to the side so its flight would approximate a parabola.

Do you think we can drag this out for another 8 pages?

 

[rdlowe]

Do you think we can drag this out for another 8 pages?

I’m hoping this thread will have more pages but contain less information than the chapter in my old physics text titled “Rotation”. There’s not far to go even counting the practice exercises. I have every confidence.

 

[hawkeye2]

I guess I'll have to dig out my copy of Sears & Zemansky from 1962.

 

[Tanglefoot]

Lads,
If you fire a bullet straight up ... whether it's fired from a rifled barrel or a smoothbore ... it will land in a different spot than it was fired from. Assuming no debris in the way, it still is affected by air friction and humidity, air density depending on elevation, and let's not forget that even if the ball goes straight up (perpendicular to the earth's surface at that point of origin) that surface is moving as the earth rotates. The spot it is fired from will move out from under it while it's in the air and the ball will come down someplace else. As far as whether it will still be rotating or in which direction that depends on so many factors I doubt it's worth the trouble and time to calculate --- but I'm equally certain that someone on this forum will try.
To answer (again) the original question: A rifle bullet fired does not go faster after it leaves the barrel. That's true for forward motion and for rotational motion also. It slows down both ways. Period. Once the ball leaves the muzzle, the only forces acting on it to change it's travel in any way are air friction, gravity, and the resistance of anything it hits, be they leaves or twigs or living critters. All of those things absorb energy from the moving projectile and act to slow it down and ultimately stop it.
When I was little one of the toys I had was a metal top -- the kind that spins. It was formed of sheet metal, maybe 4 inches wide at it's widest point tapering to a rounded point on the bottom and it had a spiral steel stem projecting from the top with a wooden handle like a drawer pull knob. By withdrawing the handle and stem and then pressing it down you started the top spinning. How fast it spun depended on how hard you pushed ---- and you could lift it by the handle to withdraw the stem again and pump it again without waiting for it to slow down, and get it going even faster ---- but no matter how fast you got the dang thing going , as soon as you quit adding energy to it, it started slowing down. Always.
Fired bullets ... ball or conicals ... act exactly the same way.
For any folks who still want to debate and are tired of this topic too, try this one:
What's the difference between a duck?

 

[Bob McBride]

What's the difference between a duck?

Ah, that's an easy one. A duck has feathers, quacks, and has four more letters in it's name...

 

[hawkeye2]

"What's the difference between a duck?"

A bicycle because a vest doesn't have sleeves.

 

[Erwan]

For any folks who still want to debate and are tired of this topic too, try this one:
What's the difference between a duck?

What's the difference between a duck ? That's a good question ...
In fact there is not really any difference except that it has both legs of the same length but especially the right leg I think...

Another important question:
Can you tell me why chickens cross roads not at right angles? ☺

 

[TNGhost]

Lads,
If you fire a bullet straight up ... whether it's fired from a rifled barrel or a smoothbore ... it will land in a different spot than it was fired from. Assuming no debris in the way, it still is affected by air friction and humidity, air density depending on elevation, and let's not forget that even if the ball goes straight up (perpendicular to the earth's surface at that point of origin) that surface is moving as the earth rotates. The spot it is fired from will move out from under it while it's in the air and the ball will come down someplace else. As far as whether it will still be rotating or in which direction that depends on so many factors I doubt it's worth the trouble and time to calculate --- but I'm equally certain that someone on this forum will try.
To answer (again) the original question: A rifle bullet fired does not go faster after it leaves the barrel. That's true for forward motion and for rotational motion also. It slows down both ways. Period. Once the ball leaves the muzzle, the only forces acting on it to change it's travel in any way are air friction, gravity, and the resistance of anything it hits, be they leaves or twigs or living critters. All of those things absorb energy from the moving projectile and act to slow it down and ultimately stop it.
When I was little one of the toys I had was a metal top -- the kind that spins. It was formed of sheet metal, maybe 4 inches wide at it's widest point tapering to a rounded point on the bottom and it had a spiral steel stem projecting from the top with a wooden handle like a drawer pull knob. By withdrawing the handle and stem and then pressing it down you started the top spinning. How fast it spun depended on how hard you pushed ---- and you could lift it by the handle to withdraw the stem again and pump it again without waiting for it to slow down, and get it going even faster ---- but no matter how fast you got the dang thing going , as soon as you quit adding energy to it, it started slowing down. Always.
Fired bullets ... ball or conicals ... act exactly the same way.
For any folks who still want to debate and are tired of this topic too, try this one:
What's the difference between a duck?

Good point about the surface rotation. Given the earth, depending on where you are standing is moving anywhere from 0 to 1650 Kilometers per hour. A projectile fired "straight" up will come down a long ways from where you are standing, miles even, unless you are at one of the poles.

So no need to duck.

 

[tenngun]

To prove to ‘possums and armadillos it’s possible

 

[bisleyjohn]

Have a look at Hatchers Notebook. Ok I know he is not talking proper powder here but the same applies. You should be able to download a pdf. I‘ve lost the link where I got mine.-sorry.

 

[MrMackc]

Good point about the surface rotation. Given the earth, depending on where you are standing is moving anywhere from 0 to 1650 Kilometers per hour. A projectile fired "straight" up will come down a long ways from where you are standing, miles even, unless you are at one of the poles.

So no need to duck.

You all are wetter than a scaldded hog!.. Then if the earth's rotation would change the place a rifle ball shot straight up the ball would always end up a ways West of the fireing spot because the earth is rotating East to West, also if you shot at a target 500 yards South ot North of you the ball would always end uo a ways West to where you shoot, so boresighting the rifle would not work worth a flip. The air is mostly rotating along with the rest of the earth and it would carry that so mentioned lead ball towards the way the wind id blowing,
I have never ever shot a BP rifle straight up but once as a pre teen I did shoot a .22 air rifle straight up under a turkey roosting in a tree 20 ' up and the pellet hit the limb under her (a hen turkey) and she kinda woke up and fell on my colley mut mix dog and he grabbed her and that evening we had roasted hen turkey for supper.
I reckon one wildassed lie here is as good as another....

 

[bisleyjohn]

Is that why they call it the blues?

 

[Tanglefoot]

If you think I'm lying, MrMac, look it up --- or talk to a physicist.