Fisica generale 1 - Moto dei razzi

Moto dei

razzi

• razzi
• accelerazione
• velocità
• equazione di Ciolkovskij

Titolo:

I razzi

Note:

13/04

Appunti:

I primi razzi risalgono ai cinesi nel 100 d.C. I razzi moderni nacquero invece con Robert Goddard (1882-1945) con il primo razzo a propellente liquido nel 1926, aprendo così l'era dell'astronautica.

Di seguito un articolo di giornale del New York Times che sminuisce lo scienziato e nega le sue tesi:

TOPICS OF THE TIMES.

A Severe Strain on Credulity.

As a method of sending a ma...

ial to the higher, untried, wr...

ard with an atheti...

tmospheric envelope. Prof...

essor Goodye...

multiple-charge rockets as a pr...

racticable, and therefore a prom...

ising device. Such a rocket, too, might carry self-recording instruments to be released as the part...

chute might send them safely to the ground. It is not obvious, however, that the instruments would return to the point of departure, indeed. It...

t, however, that the instrum...

of an interplanetary distan...

f a few hundred or thousand yards aw...

t a slight inconvenience, at least from the scientific standpoint...

iring line. It is when one considers the multip...

rocket as a traveler to the...

the more than one begin...

touch and looks ag...

to see if the date announcing...

ouncing the professor's pr...

press and hope aga...

ain that he is wor...

king under the auspices of the Sm...

ithsonian Institution. It does a...

y and therefore the impulse to...

to more than doubl...

fy the practicality...

ter such a purpose must be-w...

or must be well, carefully an...

carefully plani...

will be annou...

nd sure to expr...

w, for- as the ro...

cket quits our air, and really starts on i...

ts longer journey, its flight would be ne...

accelerated nor maintained by t...

by the explosion of the charge i...

the plan that is unknown is to...

ty-fundamental law of astronom...

nd amity. J...

uss B...

as B...

uss Bansvennd this choos...

down, no few... and fir, are ble...

ndse...

That Professor Goddard, with his “chair” in the Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react –to say would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.

But there are such things as intentional mistakes or oversights, and, as it happens, Vensen, who knew –and perhaps saw as the bystanders assumed– and, besides, a surprising amount of evidence deliberately concealed by the three same mistakes “Professor” forecasts mean to make. For the Frenchman, they do not dissuade or foot forth-driven with all the eagerness of competitive and commercial activity, wasted in the process of obliterating the heresy where an explosion would not have had in the slightest degree the effect of releasing them from their dreadful slav–

ery. That was one of Vensen’s few scientific slips, or else it was a deliberate tip aside from delicate accuracy, perchance from humble as a reman, but his luck is not so easily explained than made by a savan who isn't writ–a novel or true love.

All the same, if Professor Goodnecessi...

rocket attained sufficient speed before it parks off the atmosphere –which is a thinkable possibility– and if its aiming takes into account all of the many details, fifteen reaches of the first flight, it may reach the moon. That the rocket could carry enough explosive to make on impact be a flash far more and bright enough to be seen from the earth by the biggest of our telescopes–that will be believed when it is done.

Titolo: Equazione di Ciolkovskij

Note: 13/04

Appunti:

• Equazione di: Ciolkovskij
• v(t) = v_i + v_g ln (^m_i/_m(t))

si parla di componente non di modulo

Konstantin Eduardovic Ciolkovskij nacque nel 1857 in Russia e fu un ingegnere e scienziato pioniere dell'astronautica. Egli teorizzò molti aspetti del volo spaziale e della propulsione missilistica. Morì nel 1935 in Russia.

Schema:

Equazione di Ciolkovskij

• v(t) = v_i + v_g ln (^m_i/_m(t))