The Identifiable Effect of Variable Washer Temperature on Predicted Parabolic Flight Patterns of Air-Pressurized Rockets; Moreover, Justifiably Qualified and Pertinent Characteristics of Seeming Gravitational Defiance are Examined to an Extent of Temperature’s Ramification and Natural Consequence by Brian Braedon and Jessie.
Background: Top
Rockets are very valuable to modern society. "NASA uses rockets to launch
things and people into space" (Dunbar). They allow us humans to transport large
quantities of materials to space just outside our atmosphere and to other
planets and space objects. "The rocket engine pushes the gases downward, and the
gases exert an equal and opposite force upward on the rockets, accelerating it
upward" (Giancoli 78). However, rockets are also a lot of fun to play with for
every-day people. Kids and adults alike launch model rockets and toy rockets all
the time for pleasure. They enjoy seeing their rockets fly so high that they
can't even see them any longer, and then trying to catch them with bare hands on
the way down. One specific type of toy rocket is the P4-2200 Air Powered
Projectile, which we will be using in this experiment. Each set comes with four
different thrust washers. These thrust washers are snapped onto the top of the
rocket pump and then the rocket is lowered on to the whole contraption. Pressure
builds up in the pump and "when the pressure is high enough to pop off the
thrust washer, the projectile blasts into the sky" (Air-Powered Projectile). The
thrust washers are called Low, Medium, High, and Super, based on how much
pressure they can hold back until they blow. The higher the pressure build-up,
the high the rocket goes. This propulsion system is different from most model
rockets, which use "a rocket motor to make them go The motor burns and propels
the rocket, the propellant in the motor burns out, the rocket coasts upward and
finally arcs over at the peak of its flight" (How Rockets Work). There are many
factors that could affect the range of the rocket, but we chose to focus on the
temperature of the thrust washers. "Over small temperature ranges, the linear
nature of thermal expansion leads to expansion relationships for length, area,
and volume in terms of the linear expansion coefficient" (Thermal Physics). This
means that each washer will expand in size if they are hotter and contract in
size if they are colder. This will undoubtedly cause the range of the rocket
with each different thrust washer to vary. However, we must keep in mind that,
since this experiment will be done outside, wind will be a huge factor in the
distance the rocket travels. We also must take into consideration the fact that
once each washer is removed from the temperature-manipulating device, they will
begin to grow colder or warmer, depending on the outside temperature.
Statement of Problem: Top
The purpose of this investigation is to find out the relationship, if any,
between the range of a rocket, tilted at a fixed angle, and the temperature of
the thrust washer inside of it.
Hypothesis: Top
We believe that the range of the rocket will be shortened due to the hot thrust washer temperatures and lengthened due to cold thrust washer temperatures. This will happen because the increased size of each washer (hotter temperatures) will allow for a looser grip in the rocket pump, thus causing the rocket to release sooner, with less pressure built up. Vice versa for the colder temperatures. The controlled variables include, but are not limited to, the elevation of the platform on which the rockets will be launched, the thrust washers, the rocket, and the rocket pump.
Method: Top
The materials needed to operate this experiment include an air pump, an air
pump adaptable model rocket, an angle adjustable base for rocket, something to
fix the angle of the base, multiple washer sizes for pressurizing rocket, a
protractor, a thermos, ice, a hot plate, a beaker, and a thermometer, and a tape
measure. Firstly, attach a washer to the rocket and prepare the rocket for
launch in an open space; furthermore, this preparation includes fixing the base
of the rocket at 45 degrees with the ground, attaching the air pump, and
securing the head of the rocket over the washer. Secondly, pump the rocket until
"blast off" and then use the tape measure to identify the distance from the
rocket's base to its landing. Repeat this step several times (this experiment
tested each washer three times for accuracy) with each size of washer. Repeat
this with colder washers. In order to chill washers, place them in a thermos
filled with ice and water for two minutes. Use the thermometer to identify and
record the temperature of the chilling water (this experiment kept water at 1
degree celsius). After two minutes remove the washer, attach it to rocket and
repeat the aforementioned steps with the same frequency of testing. Repeat
experiment with heated washers as well. In order to heat the washer, use a hot
plate to heat water in a beaker. Place the washer in the heated water for two
minutes (this experiment kept heated water at 80 degrees celsius). Remove the
washer and secure it onto rocket. Repeat this with same frequency as the two
earlier testings.
Images of Setup: Top
Results: Top
Summary of Results: Top
After conducting our experiment, we found that there was not much notable
difference between the distances of the cold washers and the regular (control)
washers. However, there was a huge difference between those two sets of points
and the extremely hot washers: the cold and regulars hovered between 40 and 60
feet, while the hot never reached farther than 20 feet.
Conclusion: Top
Our results showed that as the temperature of the washers got colder, the
further the rockets went. However, the small distance between the 1 C cold
trials and the 10 C regular control trials didn't reveal much difference between
the distances the rocket travelled; in fact, the average distance of the cold
low washer was less than the average of the regular low washer. Our hypothesis
stated that the range of the rocket will decrease as the temperature of the
thrust washer increases. This hypothesis was correct: the cold and regular
washers thrust the rocket much farther (values ranged from 31.7 to 60.5 feet)
than the hot washers did (values ranged from 6.6 to 16.5). Obviously the
temperature had some sort of effect on the distance the rocket travelled because
of the drastic difference between the 1 C and 10 C washers and 80 C washers.
This effect described in the hypothesis occurred because as materials gain heat,
they expand in length and as materials lose heat, they contract. Since the
washer had expanded during the hot trials, it became looser on the mount and
required less force from the pressure inside the mount to blow off and thrust
the rocket forward. Since the temperatures in the cold and regular trials were
so similar, the forces they required to blow off were very similar and
therefore, the distances travelled by the rockets in those trials were within
the same range. If the experiment had been done with washer temperatures colder
than 0 C, then it would have taken even more pressure to blow the rocket off the
mount (it also may not have been possible to generate that much force as it was
hard to launch even the cold temperature we used) and the rocket would have gone
even further because of the huge amount of pressure under the washer. Our main
source of error was measuring the distance that each rocket. We only had a small
three meter tape measure, so it was very inaccurate when we measured 30+ yard
distances. We tried to prevent this by measuring 40 yards from the mount as a
consistent distance so that we didn't have to waste so much time measuring all
the way from the mount. Some suggestions to improve our procedure would be to
use a much larger tape measure to measure the distances the rockets travelled
and to use all four types of washers: low and medium (the ones we used), in
addition to high and super. Other suggestions include using a wider range of
temperatures. We did prove our hypothesis, but a middle-ground temperature
around 50 C or 60 C and a super cold temperature around -10 C or -20 C would
have solidified our results. We also used two different low and medium washers
for our experiment without tracking which were used for each trial, so being
consistent in the use of certain washers would be more accurate.
Related Links: Top
Has some good material on the progress of rockets in recent years.
http://bulbapedia.bulbagarden.net/wiki/Team_Rocket
Includes valuable background on the semblance of a team of rocket scientists
Displays the work of SpaceX's rocket plans for the next few decades
https://www.youtube.com/watch?v=yQf5cGPcP48
Instructional video showing how to properly use a model rocket
http://www.shopcherrycreek.com/directory/johnny_rockets
Website exemplifying the consumer possibilities surrounding the intrinsic properties of rockets tantamount to the aspirations of astrophysicist Johnny
Bibliography: Top
"Air-Powered Projectile." Labs Activities and Other CoolStuff RSS. N.p., n.d. Web. 28 Oct. 2014. <http://www.arborsci.com/air-powered-projectile>.
Dunbar, Brian. "What Is a Rocket?" NASA. NASA, 27 May 2014. Web. 28 Oct. 2014. <http://www.nasa.gov/audience/foreducators/rocketry/home/what-is-a-rocket-k4. html>.
"How Rockets Work." Fly Rockets. N.p., n.d. Web. 28 Oct. 2014. <http://www.flyrockets.com/work.asp>.
Giancoli, Douglas C. Physics. 6th ed. Upper Saddle River, NJ: Pearson Education, 2009. Print.
"Thermal Expansion." Thermal Expansion. HyperPhysics, n.d. Web. 28 Oct. 2014. <http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thexp.html>.