Answer:
b. flat rotation curves in spiral galaxies
Explanation:
Dark matter accounts for majority of the matter in the universe (about 85%). It is considered to be composed of subatomic particles which are yet to be discovered. Dark matter cannot be observed because it does not emit light that can be detected. Only its gravitational effect is visible.
Astronomers when calculated the mass of the visible matter and tried to account for the observed speed of stars in the galaxy, there was a mismatch. To understand what caused this mismatch, astronomers gave name to the invisible matter as the Dark Matter.
The expected velocity of stars should decrease away from the near the center of the galaxy but a constant velocity of stars was observed that is a relatively flat rotation curve was obtained.
Thus, flat rotation curves in spiral galaxies in an evidence of Dark Matter.
<span>Cele mai mari acumulari de apa sunt calul alb, negreni , pe raul baseu mileanca pe paraul podriga catamarasti si dragasani pe raul sidna
ExistÄ douÄ categorii de lacuri:
Lacuri hidroenergetice:Lacul Stânca-Costești,pe Prut
Iazuri:cu frecvenČ›Ä mare:DracČ™ani,pe Jijia</span>
Major volcanic events that have occurred within the Ring of Fire since 1800 included the eruptions of Mount Tambora (1815), Krakatoa (1883), Novarupta (1912), Mount Saint Helens (1980), Mount Ruiz (1985), and Mount Pinatubo (1991).
Answer:
Some types of geological events and changes that occurred at divergent plate boundaries are seafloor spreading, volcanoes, earthquakes, and ocean formation. ... Some types of geological events and changes that occurred at convergent plate boundaries are islandchainsb, mountains, earthquakes, and volcanoes.
Explanation:
Hope this helps :)
Japan! :D is the correct answer :)
