Does a RB travel with constant rotation, or accelerate?

[rdlowe]

I don’t want this physics thread get more than 10 pages long without having any equals signs in it.
=

 

[FishDFly]

After 10 pages there is no definitive answer.

 

[Bob McBride]

There is a definitive answer to the question posed in the OP’s title. Neither.

 

[Loren Rytter]

If the earth rotates East to West the sun would set in the east.

 

[Bob McBride]

If the earth rotates East to West the sun would set in the east.

Yes sir. The land is moving East, which is why we leave the sun behind every evening.

 

[Nameless Hunter]

And the expansion of the universe...

And let's not even bring up the impact of dark matter...

 

[rdlowe]

Summer, 2014, ESA mission planning committee:

Guy 1: As you can see, we’ve calculated and accounted for the correct atmospheric and kinetic braking action to touch the Schiaparelli rover down safely on the surface, well within structural tolerances...
Guy 2 :...but?
Guy 3: ...but we feel like there’s some torque vector that’s not quite being accounted for.
Guy 2: Very well. Let’s consult the muzzleloader forum and see if we’ve missed anything.

2 years later:
European Mars Lander Crashed Due to Data Glitch, ESA Concludes

And now you know the rest of the story.

 

[George]

Ten thousand comedians out of a job, but everybody still wants to be one.

If anyone bothered to read the appropriate section of Hatcher's notebook, they would have seen that standard bullets came back to earth base first. That would seem to mean that the bullet was still spinning enough to be stable at the end of its long flight up and down, it didn't tumble down.

Oh, and BTW, they didn't land miles away but came straight back down.

Spence

 

[Col. Batguano]

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?

Yes.

 

[Tanglefoot]

Somebody a couple pages back wanted an equals sign. Here y'go.

<Entire thread preceding this entry> = Enough fun for me.

Going off gratefully to another topic .......... Bye, y'all.

 

[tenngun]

I think threads die when people feel they have nothing to add to it, or they spin off and violate some forum rules, but that’s rare.
How do you age a tin cup? Trade gun wiping sticks? No one has wanted to take the time to add to it.
I am thinking of writing a book
Zen and the at of muzzle loading.

 

[bisleyjohn]

Is this the ‘at’ as in wez u at, or as in the ‘at’ you doff?

 

[tenngun]

Is this the ‘at’ as in wez u at, or as in the ‘at’ you doff?

That’s spell check combined with fat fingers

 

[Carbon 6]

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.

I think you should recheck the math on that, maybe the physics too.

Under what conditions would it come down "miles away" ? Did it hit an airplane ?

 

[MrMackc]

Now wait ! Is that magnetic poles or geographical poles ? And isnt there a wobble even at the poles so even with the slightest wobble the projectile would not return to its launch location ??? and just how many "S's" are in physississt ?
Is that like M eye SS eye SS eye Pee Pee eye ??

Yep, kinda like that.....Good night Grandpa!

 

[Carbon 6]

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.

Can you explain to me how that works ? Is gravity different at the poles ? are the physics different ?

 

[rdlowe]

Perhaps the assumption is that the Earth will rotate beneath the bullet as it goes straight up and down (which wouldn’t account for the same rotation at the moment the bullet was fired)?

 

[Tanglefoot]

Good night, John Boy.

 

[rdlowe]

Thought you were already in bed, Tanglefoot

 

[Bob McBride]

Perhaps the assumption is that the Earth will rotate beneath the bullet as it goes straight up and down (which wouldn’t account for the same rotation at the moment the bullet was fired)?

Reminds me of Einstein's thought experiment that Hawking talked about in 'A Brief History of Time':

A man bounces a ball on a flatcar on a moving train. To him the ball is bouncing straight up and down. Another man is standing beside the tracks and watches the man bouncing the ball as he goes by. To him the ball is flying in a long arc. Both things are true. The ball IS bouncing straight up and down, and it IS bouncing in an arc. All depends on your frame of reference....