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Quiz! for this lesson.
Click on extended
mission for more fun activities, links, and resources on this topic.
Consider this topic for your Final Project!
Your
mission consists of two parts.
-
Write a one-page opinion paper
on whether or not we should return to the Moon. List all of your
reasons why (or why not) and explain them. You can describe scientific
and commercial ventures. Use and cite at least 3 sources.
OR
-
Submit a drawing of an original
design for a ship that would be able to return us to the moon. Label all
of the parts of the ship. Write a short description that includes
a list of the components of the lunar ship (propulsion systems, energy
consumption, communications systems, guidance systems, etc.) and a timeline
of the mission, numbers of persons in your crew, and the major goals of
your expedition.
AND
-
Complete the Moon Math problem.
Use
any of these links below for ideas to get you started!
Include
your Moon ship description or your opinion paper with the answer to the
Moon Math problem in the text box of the Comm
Link. Attach your drawing as a .jpg.
Moon Math:
You
must include an answer to this question with your assignment to receive
full credit. It’s okay if you don’t get it right just give it your best
shot. Explain how you got your answer!
Long ago,
Sir Isaac Newton gave us a mathematical description of how one object affects,
and is affected by, the gravitational force of another object. Many, many
years of observations have proven this description to be accurate (at least
for masses like those of the planets). Newton's Law of Gravitation states:
The force between any two objects having masses M1 and M2 separated by
a distance R is an attraction along the line joining the objects and has
a magnitude of:
F = (G x M1 x M2) / (R x R).
G is the universal gravitational
constant, which has a value of 6.6732 x 10^-11 newton-meters^2/kg^2 for
all pairs of objects. (A "newton" is a unit of force that physicists use.
It is defined to be the amount of force needed to accelerate a 1 kg mass
at 1 meter per sec^2. A newton, as a unit of force, is fairly small, like
a millimeter is a small unit of distance or a microsecond is a small unit
of time.)
How do we know what speed an
object in orbit around a planet or a moon must travel to maintain it's
orbit and not be pulled down to the surface by gravity? The orbital
velocity equation tells us how!
Question: The Apollo spacecraft
must be travelling at what speed in order to remain in a 200 kilometer
orbit above the moon?
The magnitude of the velocity
can be computed exactly from the laws of gravitational motion. To remain
in orbit, a spacecraft must travel at a very high velocity. The required
velocity is dependent on gravity and decreases with increasing altitude
(i.e., distance) as shown:
v=(GM/r)^0.5
or
v= SQRT (GM/r)
where V is the orbital velocity,
R is the radius of the orbit, and G is the local acceleration of gravity.
You can work the problem from scratch or use the shortcut below:
Shortcut: GM (gravitational
constant times the mass of the moon) = 0.0049 (10^6 kilometers^3/seconds^2)
Hint: First find the radius
of the moon and then add that the orbital altitude to answer the problem!
This
search engine is from NASA.
Don't forget to show your work!
Your assignment will be
assessed using the following criteria. If your work meets all of
the criteria below it will be considered exemplary. If one or two
of the criteria are not met your work will be considered satisfactory.
If more than three criteria are not met your work will be considered unsatisfactory
and you will be asked to resubmit it. |
