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Beginner's
Guide to Propulsion
Air
Temperature and Kinetic Energy Activity
If
so instructed by your teacher, print out a worksheet page for these
problems.
Before you begin:
 After reading
the text on Air Temperature
and the Kinetic Theory of Gases,
we are now going to do some mathematics using the kinetic energy formula,
KE = mv^{2} / 2, where
KE is the kinetic energy of the
gas, m is the mass, and
v is the velocity.
 First, a short
review of scientific
notation (http://www.webmath.com/sn_convert.html). Scientific
notation is often used when numbers are very large or very small.
Its form is always a decimal number times a power of ten. [Note:
For more information on scientific notation, click here
(http://www.math.toronto.edu/mathnet/questionCorner/scinot.html).]
Examples:
3456789 = 3.456789 x 10^{6
}123.4567 = 1.234567 x 10^{2
}0.003456 = 3.456 x 10^{3
}0.0000000065432 = 6.5432 x 10^{9}
 Next, a brief
explanation of how to find the mass of a gas is located at the Periodic
Table (http://www.chemicalelements.com/show/mass.html). It lists
all the elements and their atomic weights in a unit called the atomic
mass unit. To convert this to kilograms, you must multiply by 1.66
x 10^{27}. This is the number of kilograms in one atomic
mass unit.
Example:
The atomic weight of oxygen is 15.9994.
15.9994 x 1.66 x 10^{27 }= 2.6559 x 10^{26}
kg. This is the mass of one atomic mass unit of oxygen.
For this activity
you will need to perform similar calculations and then use your answers
in the kinetic energy formula.
ANSWER THE FOLLOWING
QUESTIONS:
 What is the name
of the branch of physics that studies the temperature of objects and
the flow of heat between objects of different temperatures?
 Temperature
is a scalar quantity with magnitude, but no direction. Can you think
of something else we commonly measure that is also a scalar quantity?
 A gas is composed
of a large number of molecules that are in __________, __________
motion.
 When
the temperature is high, the molecules move _____________.
 What
is the name of the device used to measure temperature?
 Temperature
is really a measure of the average kinetic energy of a gas. What is
the formula used for determining kinetic energy?
 Convert these
two numbers to scientific notation: 456.2332 and 0.00002349.
 Find the mass
of one atomic unit of each of the following five gases: Hydrogen,
Helium, Oxygen, Nitrogen, and Neon.
 Assume the average
velocity of oxygen at room temperature is 480 meters per second. Using
the kinetic energy formula along with your answer from question 8,
calculate the kinetic energy for oxygen.
 Assume the average
velocity of nitrogen at room temperature is 510 meters per second.
Using the kinetic energy formula along with your answer from question
8, calculate the kinetic energy for nitrogen.
 Assume the average
velocity of hydrogen at room temperature is 390 meters per second.
Using the kinetic energy formula along with your answer from question
8, calculate the kinetic energy for hydrogen.
 Write a sentence
or two summarizing what you learned from this activity.

Related Pages:
Standards
Worksheet
Propulsion Activity Index
Propulsion Index


