Re: if I built a giant cannon

On Mar 26, 12:50 pm, "Androcles" <Headmas...@xxxxxxxxxxxxxxxx> wrote:
"Randy Poe" <poespam-t...@xxxxxxxxx> wrote in message

news:cdb61dfe-5948-4f64-b0e6-86e2ba2b32e3@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| On Mar 25, 10:50 pm, "fruitbat" <a...@xxxxxxxxxxxxx> wrote:
| > (a) Assume a very big cannon could reliably fire a shot from New York to
San
| > Francisco.
|
| These cannon are called "missile silos". The shots are called
| "ballistic missiles".

Almost correct, but he means the propellant remains with the silo (or just
above it)
and the missile takes the propellant with it, only becoming ballistic after
reaching
a desired altitude. The desired altitude for the propellant shut off is
usually much
lower for the cannon case than the missile case.
|

| > The shots are accurate and easily reproduced.
| > Now we take the cannon to San Francisco and fire back at New York.
| > Would the shot end up as exactly in New York?
|
| No. The earth rotates.

Dear San Francisco:
We are sending you an ICBM by airmail. Enjoy.
Love, New York.

Dear New York:
We are returning your kind gift.
Love, San Francisco.

One would hope the SF cannon-silo engineers had allowed for that in the
NY->SF case and could reliably return fire.

One would hope so. However, OP explicitly stated that
we don't make any such corrections in his questions.

Is this that inability-to-read-your-own-language thing
again?

| It's on an inclined, probably eccentric orbit with an inclination
| of about 41 degrees and an eastward component of velocity. The
| next point of intersection with earth might be at -41 degrees
| latitude.

You are frame hopping, Poe.
The shot does not have an eastward component of velocity relative
to New York, but it will fall further than it climbed.

The earth rotates. Something given a purely radial boost
has already been given a tangential boost by the earth's
surface. That's why US launches are from a latitude near
the equator, to maximize the effect.

- Randy
.

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