Explain why we observe distant galaxies to be moving away from us and therefore believe that the universe is expanding, but we don't see individual galaxies or clusters expanding
What will be an ideal response?
The pull of gravity works to slow the expansion rate of the universe. Therefore, in dense regions such as galaxies and clusters of galaxies, gravity is able to overcome the expansion and keep these objects from expanding. However, on larger scales, where the average density is lower, gravity does not have as strong an effect, and therefore the expansion continues between clusters of galaxies.
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Ideal Gas Law: How many moles are there in 2.00 kg of copper? The atomic weight of copper is 63.5 g/mol and its density is 8.90 g/cm3.
A. 15.3 B. 31.5 C. 51.3 D. 53.1
The sentence “Brass is an element in the periodic table” is a logical statement.
Indicate whether the statement is true or false
Based on the given right ascensions and declinations, which of the following stars lies closest to the south celestial pole on the celestial sphere?
A) Sirius: RA = 6hr 45m, dec = -16°42' B) Canopus: RA = 6hr 24m, dec = -52°41' C) Alpha Centauri: RA = 14hr 40m, dec = -60°50' D) Arcturus: RA = 14hr 16m, dec = +19°11' E) Vega: RA = 18hr 37m, dec = +38°47'
From hottest to coolest, the seven letters for the star types are ________
Fill in the blank(s) with correct word