Answer:
<u>Geocentric Model</u>: - this model is Earth Centered
-Retrograde motion is explained by epicycles
<u>Heliocentric Model</u>: - This model is Sun Centered
-Retrograde motion is explained by the orbital speeds of planets
<u>Both models</u>:- Epicycles and deferents help explain planetary motion
-Planets move in circular orbits and with uniform motion
-The brightness of a planet increases when the planet is closest to Earth
Explanation:
Retrograde motion is an apparent change in the movement of the planet through the sky. Ptolemy's model of the solar systems was geocentric, where the Sun, Moon, planets and start all orbit the Earth in perfectly circular orbits. However this perfectly circular orbits around the Earth did not explain the occasional retrograde motion of the planets. In the Copernicus' heliocentric model, retrograde motion of planets is naturally explained. The explanation for retrograde motion in a heliocentric model is that retrograde occurs roughly when a faster moving planet catches up to and passes a slower moving planet.
Answer:
26 cantons
Explanation:
Zürich (ZH)
Bern / Berne (BE)
Luzern (LU)
Uri (UR)
Schwyz (SZ)
Unterwalden (Obwalden (OW) / Nidwalden (NW))
Glarus (GL)
Zug (ZG)
Freiburg / Fribourg (FR)
Solothurn (SO)
Basel (Basel Stadt (BS)/ Basel Land (BL))
Schaffhausen (SH)
Appenzell (Appenzell Ausserrhoden (AR) / Appenzell Innerrhoden (AI))
Sankt Gallen (SG)
Graubünden (GR)
Aargau (AG)
Thurgau (TG)
Ticino (TI)
Vaud (VD)
Valais / Wallis (VS)
Neuchâtel (NE)
Genève (GE)
Jura (JU)
<span>Life expectancy in Sub-Saharan Africa is lower than that of more-developed nations.
Poverty is prevalent in Sub-Saharan Africa. </span>It is also<span> is the region with the highest prevalence (percentage of population) of </span>hunger<span>. When a person is malnourished as well as undernourished, he or she has lower immunity and is more prone to have diseases. </span>
Answer:
Human activity is the main cause of climate change. People burn fossil fuels and convert land from forests to agriculture. ... Burning fossil fuels produces carbon dioxide, a greenhouse gas. It is called a greenhouse gas because it produces a “greenhouse effect
