Answer: Ptolemaic system, also called geocentric system or geocentric model, mathematical model of the universe formulated by the Alexandrian astronomer and mathematician Ptolemy about 150 CE and recorded by him in his Almagest and Planetary Hypotheses. The Ptolemaic system is a geocentric cosmology; that is, it starts by assuming that Earth is stationary and at the centre of the universe. The “natural” expectation for ancient societies was that the heavenly bodies (Sun, Moon, planets, and stars) must travel in uniform motion along the most “perfect” path possible, a circle. However, the paths of the Sun, Moon, and planets as observed from Earth are not circular. Ptolemy’s model explained this “imperfection” by postulating that the apparently irregular movements were a combination of several regular circular motions seen in perspective from a stationary Earth.
Explanation:
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Answer:
R = 480 Ohm
Yes, the current is steady since the power supply is a constant 12V (comming from the battery).
Explanation:
U=I*R
R = U / I
U = 12 V
I = 0.025 A
R = 12 / 0.025
R = 480 Ohm
Answer:
Explanation:
Based on the scenario being described within the question it can be said that the most likely reason for this misconception would be that the spiral galaxies looked like clouds of gas and dust through telescopes because of their distance from Earth. During that time telescopes were still not as advanced and could only see so much, nowadays they are much more advanced and these galaxies are being analyzed and understood more clearly.
Answer: The correct answer would be YYRr and Y_Rr
Explanation:
Let us denote Y and y be the alleles of the gene responsible for seed color and R and r be the alleles of the gene responsible for seed shape. Capital letter is for dominant allele and small letter is for recessive allele.
Being dominant traits, both the parents should have at least one dominant allele of both the genes. It is because the phenotype of both parents is yellow and round seeds.
In addition, F1 shows single phenotype for seed color but both phenotype for seed shape. The presence of recessive phenotype in F1 indicates that both the parents must be heterozygous for seed shape, that is, Rr.
However, for seed color, it is possible that either one or both were homozygous, that is, either both YY or one parent is YY and another parent is Yy.
Answer: What are the numbers of valence electrons for each atom?
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cations and anions combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral ionic compound.
The oxidation states are known by their ability to gain or lose electrons which is decided by the number of valence electrons.
