Corso di ASTRONOMIA DI BASE - 2012

Corso di
ASTRONOMIA DI
BASE - 2012
Esercitazioni: MOVIMENTO DEI CORPI
Allegato alla seconda serata del corso – 09/02/2012.
CORSO DI ASTRONOMIA DI BASE
Esercitazione alla prima seconda del corso di astronomia di base 2012 di Skylive-123 Stella
LINK UTILI PRIMA DELL’ESERCITAZIONE
Il materiale relativo alla serata, e necessario alle esercitazioni, può essere visionato ai link che seguono:
123 Stella

Coordinate terrestri e sfera celeste
http://www.skylive.it/123StellaFisica/Forza_di_Gravita_Massa_Peso_sui_Pianeti.aspx
SKYLIVE TELESCOPI REMOTI

Il movimento dei corpi nella storia dell’uomo
http://www.skylive.it/AstronomiaVisuale/Astronomia_Visuale_storia_del_movimento_dei_corpi_celesti.asp
x

L’evoluzione del concetto di Gravità
http://www.skylive.it/Astrofisica/Astrofisica_Forza_Gravita_Newton_Keplero_Einstein.aspx

La materia oscura
http://www.skylive.it/Astrofisica/Astrofisica_CorpiCelesti_Materia_Oscura.aspx
Inoltre, è possibile (e consigliato) scaricare la dispensa in PDF con la presentazione delle slide diffuse
durante la serata, al link che segue:
http://www.skylive.it/EventoSerale_Dettagli.aspx?Id=76
MOVIMENTO DEI CORPI
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CORSO DI ASTRONOMIA DI BASE
ESERCITAZIONI
1. Nota l’accelerazione gravitazionale sulla superficie terrestre, pari a 9,8 m/s 2, indicare
l’accelerazione gravitazionale che la Terra esercita su un corpo 100 volte più distante.
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CORSO DI ASTRONOMIA DI BASE
2. I pianeti si muovono più velocemente in prossimità del perielio. Giustificare questa
osservazione attraverso la Legge di Newton.
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CORSO DI ASTRONOMIA DI BASE
3. Ipotizziamo un corpo di una certa massa. Questo corpo viene “pesato” su vari pianeti del
Sistema Solare. Riordinare i pianeti in base al peso (in ordine crescente) che il corpo
sperimenterà sui vari pianeti sapendo che:
Mercurio g = 3,703 m/s2
Giove g = 25,93 m/s2
Venere g = 8.872 m/s2
Nettuno g = 11,28 m/s2
Marte g = 3,782 m/s2
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CORSO DI ASTRONOMIA DI BASE
4. Con riferimento all’esercitazione n°3, indicare su quali pianeti il corpo avrebbe un peso
superiore a quello sperimentato sulla Terra.
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CORSO DI ASTRONOMIA DI BASE
5. Indicare in che modo appaiono diverse l’orbita terrestre rispetto al Sole e l’orbita di due stelle,
tra loro di massa simile, in un sistema binario.
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CORSO DI ASTRONOMIA DI BASE
6. Indicare la distanza massima teorica alla quale agisce la forza di gravità di un corpo.
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CORSO DI ASTRONOMIA DI BASE
7. Se il Sole si spegnesse, ce ne accorgeremmo dopo 8 minuti. Se qualcuno lo togliesse ce ne
accorgeremmo subito. Indicare per quale motivo la gravità non viola il limite imposto dalla
Relatività Ristretta di Einstein in merito alla velocità massima raggiungibile.
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CORSO DI ASTRONOMIA DI BASE
8. Quale evento astronomico indicano le pietre di Stonehenge?
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CORSO DI ASTRONOMIA DI BASE
9. In quale modo Tolomeo riuscì a spiegare il moto retrogrado dei pianeti?
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CORSO DI ASTRONOMIA DI BASE
10. Spiegare in breve su quali ragioni si basa la MOND.
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CORSO DI ASTRONOMIA DI BASE
QUESTIONARIO BREVE
1. La lente gravitazionale è:
o Un meccanismo di meccanica quantistica che consente di osservare corpi molto piccoli
altrimenti non osservabili
o Un meccanismo previsto dalla relatività che consente di capire se tra noi e corpi distanti
esistono masse gravitazionali che non possiamo scorgere ad occhio
o Uno strumento di osservazione del cielo basato su lenti di tipo particolare, che mostrano i
legami gravitazionali tra corpi celesti
2. La MOND prevede:
o Il raddoppio delle masse nella legge di gravitazione universale
o Il cubo della distanza nella legge universale
o La relazione con la distanza anziché il suo quadrato oltre certe distanze
3. I primi indizi di un sistema planetario con il Sole al centro risalgono a:
o Tolomeo
o Ipparco
o Sumeri
4. Tycho Brahe fu fondamentale per:
o I dati raccolti durante la sua attività a Uraniborg
o Il modello del sistema solare sviluppato
o Aver scoperto l’omonimo cratere sulla superficie lunare.
5. La Prima Legge di Keplero ci assicura che:
o I pianeti sono più veloci nei pressi del fuoco orbitale occupato dal Sole;
o Le orbite planetarie sono ellittiche;
o Il rapporto tra quadrato del periodo di rivoluzione e cubo dell’asse maggiore orbitale è
costante.
6. La Sala dei Tori a Lascaux rappresenta, fin da 12.000 anni fa:
o La galassia di Andromeda, visibile ad occhio nudo;
o L’ammasso aperto delle Pleiadi;
o L’ammasso aperto delle Iadi, nei pressi dell’occhio del Toro.
7. Aristotele riuscì a stabilire, pur sbagliando, la dimensione del Meridiano Terrestre:
o Grazie alle misurazioni stellari di Ipparco;
o Grazie alla differente ombra proiettata dal Sole in due località distanti;
o Grazie alla differente altezza della Stella Polare in Egitto e in Grecia
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CORSO DI ASTRONOMIA DI BASE
8. Aristarco di Samo fu reso celebre grazie a:
o Misurazioni delle distanze tra Terra, Luna e Sole;
o Primo modello geocentrico del Sistema Solare;
o Prime carte del cielo.
9. Il modello Copernicano ebbe il merito di:
o Porre l’uomo al centro dell’universo
o Estrarre leggi osservative valide in qualunque sistema
o Spiegare l’alternanza del giorno e della notte
10. Quel che Newton non riusciva a spiegarsi era:
o Perché il Sole e la Terra non orbitassero entrambi intorno ad uno stesso baricentro mentre è
chiaramente la Terra che orbita intorno al Sole;
o Come poteva una mela cadere proprio sulla sua testa;
o Come poteva la gravità essere immediata a distanze infinite.
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