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.

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Statement of Problem



Images of Setup


Summary of Results


Related Links





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

Data File : text .:. Excel

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.

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

Instructional video showing how to properly use a model rocket

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. <>.

Dunbar, Brian. "What Is a Rocket?" NASA. NASA, 27 May 2014. Web. 28 Oct. 2014. < html>.

"How Rockets Work." Fly Rockets. N.p., n.d. Web. 28 Oct. 2014. <>.

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. <>.