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 09/02/2012 1 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. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 2 CORSO DI ASTRONOMIA DI BASE 2. I pianeti si muovono più velocemente in prossimità del perielio. Giustificare questa osservazione attraverso la Legge di Newton. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 3 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 _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 4 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. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 5 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. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 6 CORSO DI ASTRONOMIA DI BASE 6. Indicare la distanza massima teorica alla quale agisce la forza di gravità di un corpo. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 7 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. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 8 CORSO DI ASTRONOMIA DI BASE 8. Quale evento astronomico indicano le pietre di Stonehenge? _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 9 CORSO DI ASTRONOMIA DI BASE 9. In quale modo Tolomeo riuscì a spiegare il moto retrogrado dei pianeti? _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 10 CORSO DI ASTRONOMIA DI BASE 10. Spiegare in breve su quali ragioni si basa la MOND. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ MOVIMENTO DEI CORPI 09/02/2012 11 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 MOVIMENTO DEI CORPI 09/02/2012 12 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. MOVIMENTO DEI CORPI 09/02/2012 13