A star of mass 2.0 ✕ 1029 kg that is 1.8 ✕ 1020 m from the center of a galaxy revolves around that center once every 2.2 ✕ 108 y
ears. Assuming that this star is essentially at the edge of the galaxy, each of the stars in the galaxy has a mass equal to that of this star, and the stars are distributed uniformly in a sphere about the galactic center, estimate the number of stars in the galaxy. (Do not round your answer to an order of magnitude.)
1 answer:
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Since the temperature of the gas remains constant in the process, we can use Boyle's law, which states that for a gas transformation at constant temperature, the product between the gas pressure and its volume is constant:
which can also be rewritten as
(1)
where the labels 1 and 2 mark the initial and final conditions of the gas.
In our problem,
, 
and 
, so the final pressure of the gas can be found by re-arranging eq.(1):
Therefore the correct answer is
<span>1. 0.75 atm</span>
which can also be rewritten as
where the labels 1 and 2 mark the initial and final conditions of the gas.
In our problem,
Therefore the correct answer is
<span>1. 0.75 atm</span>
Answer:
The helicopter uses 35 gallons to fly for 5 hours.
Explanation:
The amount of gas that a helicopter uses for flying varies directly proportional to the number of hours spent flying.
g ∝ T
where g represents amount of gas and T time of flight.
Then,
The helicopter files 4 hours and uses 28 gallons of fuel.
Here, g₁= 28 gallons, T₁=4 hours
g₂=?, T₂=5 hours.
⇒28×5= g₂×4
⇒ g₂×4=28×5
gallons
The helicopter uses 35 gallons to fly for 5 hours.