CORRECT!!
, Which of the following is true?
a) The sun is roughly 100x more massive than the Earth
b) The sun is roughly 1000x more massive than Earth
c) The sun is roughly 100x more massive than all the planets combined
d) The sun is roughly 1000x more massive than all the planets combined
e) The sun is roughly as massive as all the planets combined - ANSWER d) The sun is
roughly 1000x more massive than all the planets combined
What is the composition of the Sun?
a) Mostly hydrogen and oxygen with a small fraction of all the other elements
b) Mostly hydrogen and helium with a small fraction of all the other elements
c) Mostly carbon and nitrogen with a small fraction of all the other elements
d) Mostly oxygen and carbon with a small fraction of all the other elements
e) Nearly equal portions of all the elements - ANSWER b) Mostly hydrogen and helium
with a small fraction of all the other elements
What do we mean when we say that the Sun is in gravitational equilibrium?
a) The hydrogen gas in the Sun is balanced so that it never rises upward or falls
downward
b) The Sun maintains a steady temperature
c) This is another way of stating that the Sun generates energy by nuclear fusion
d) There is a balance with the Sun between the outward push of pressure and the
inward pull of gravity
e) The Sun always has the same amount of mass, creating the same gravitational force.
- ANSWER d) There is a balance with the Sun between the outward push of pressure
and the inward pull of gravity
How does the Sun generate energy today?
a) Nuclear fission
b) Nuclear fusion
c) Chemical reactions
d) Gravitational contraction
e) By gradually expanding - ANSWER b) Nuclear fusion
What is the approximate threshold temperature where hydrogen fuses into helium?