Answer:
1) 63241 AU make a light year.
2) , 92914853miles
The astronomical unit gives a simple way to compare distance between planets and the Sun, using the distance from the Sun to Earth as an started point.
Explanation:
1) How many AU make up a light-year?
A light year is the distance that light can travel in one year
The speed of light has a value of
That can be express in units of kilometers and years:
--
--
Therefore, the distance can be found by means of the equation for average velocity.
(2)
Then, t will be equal to 1 year ()
However, an astronomical unit is defined as the distance between the Earth and the Sun ().
Therefore, to know how many astronomical units make a light year:
Hence, 63241 AU make a light year.
2) What is an astronomical unit (AU) in miles and kilometers? Why is it useful for understanding the distances to planets?
As in was already said, an astronomical unit has a value of
Then, it can be express in units of miles:
⇒
The astronomical unit gives a simple way to compare distance between planets and the Sun, using the distance from the Sun to Earth as an started point.
To find the temperature it is necessary to use the expression and concepts related to the ideal gas law.
Mathematically it can be defined as
Where
P = Pressure
V = Volume
n = Number of moles
R = Gas constant
T = Temperature
When the number of moles and volume is constant then the expression can be written as
Or in practical terms for this exercise depending on the final temperature:
Our values are given as
Replacing
Therefore the final temperature of the gas is 800K
It is determined by the nature of the green light. Because lasers create light at almost a single frequency, green laser light would appear as a thin line of pure green. Other sources of "green" light emit light at a variety of frequencies, including yellow and blue, resulting in a strong green band in the center that fades into blue-green and yellow-green at the borders.
For example, here’s a graph of the spectrum of a green LED, showing the color range: Attachment #1
and here’s a graph of the transmission spectra of several standard photographic filters, including green: Attachment #2
Learn more about the color spectrum:
#SPJ2
Answer:
The mass rate of the cooling water required is:
Explanation:
First, write the energy balance for the condensator: The energy that enters to the equipment is the same that goes out from it; consider that there is no heat transfer to the surroundings and kinetic and potential energy changes are despreciable.
Where w refers to the cooling water and s to the steam flow. Reorganizing,
Write the difference of enthalpy for water as Cp (Tout-Tin):
This equation will let us to calculate the mass rate required. Now, let's get the enthalpy and Cp data. The enthalpies can be read from the steam tables (I attach the tables I used). According to that, and
can be calculated as:
.
The Cp of water at 25ºC (which is the expected average temperature for water) is: 4.176 . If the average temperature is actually different, it won't mean a considerable mistake. Also we know that
, so let's work with the limit case, which is
to calculate the minimum cooling water mass rate required (A higher one will give a lower temperature difference as a result). Finally, replace data: