Presentation on theme: "BOTTLE ROCKET INVESTIGATION"— Presentation transcript:
1BOTTLE ROCKET INVESTIGATION An investigation is really a series of experiments all trying to solve different pieces of the same problem.Your task is to determine what it takes to propel a pop bottle rocket to its maximum distance.
2Background Information Your research.What do you already know?What have others who are working similar problems found out that might help you with your problemExamples of background info might include:What components do rockets have that you could or shouldinclude in your rocket design? What size and shape should these components be?How should the weight be distributed?What creates the thrust to launch a rocket?
3The main part of the rocket will be A 2 liter bottle. All information in this presentation is taken fromThe main part of the rocket will beA 2 liter bottle.Don’t cut or puncture the pressure chamber (bottle)Don’t use: hot/boiling waterknives or razor bladeschemical solvents
4FLOUNDER NOSE CONEThe first type illustrated here is called "The Flounder".It is the easiest to make but lacks flight stability. Thecone is made from poster board or tag board. Youcan make the cone by simply cutting a large circle outof the poster board (about a 6 inch radius). Cut a linefrom the outer edge of the circle to the center on theradius. Overlap the cut edges and turn the circle whileholding one edge stationary until you get the desiredcone shape. Secure the cone with staples or tape.Attach to the bottle with tape or similar adhesive.
5As I mentioned before "The Flounder" lacks flight stability, this can be fixed to a degree by pressing a small lump( a few ounces) of clay to the inside of the nose cone.This will add mass to the cone and keep your rocketfrom flipping end over end while in flight. This newand improved rocket could be called "The Bullet".You can also put a golf ball or tennis ball in the nose conefor top weight.
6“Bertha” Nose Cone The "Bertha Series" nose cones are easy to make as well but require a little attention to detail. The"Bertha" nose cones are made by cutting the bottomoff a spare bottle and attaching the top portiononto the pressure chamber. One strip of tape shouldbe enough to hold the cone on. (Note: Nevercut the pressure chamber) Using this methodyou can even make your "Bertha" rocket two orthree nose cones tall! (we call that a "Big Bertha")Within the top nose cone you can add a small lumpof clay to increase the mass. Pay attention to keepall the cones in a straight line. A curvy rocket willnot be safe coming off the launcher.
7“Space Needle” Nose Cone The "Space Needle" style of nose cone can be madefrom a spare bottle, empty paper towel roll, anda tennis ball or racket ball. This type of nose coneadds a great deal of inertial mass to the rocket andmakes it really stable. Simply, attach the towel rollto the top of a single Bertha nose cone and then fixthe tennis ball to the top of the roll. Take your timebuilding this set up because you want the entireassembly to be straight as an arrow.Cut tabs in an index card and glue or tapethe card to the tube. This will hold the tubeupright. Then glue or tape the tabs onto thenose cone top.
8Additional Ideas: A used foam pool noodle will make a fantastic soft, spongy nose cone. Use a serrated knife toshape the foam noodle and hot glue it onto yournose cone.Plastic egg halves will also fit nicely onto the"Space Needle" assembly.
9FINS Fins are the guidance system for your rocket. Without them a rocket would tumble end over end. Fins can give your rocketlife and beauty. Fins can portray aggressive power or aerodynamicgrace. However, fins tend to be the single greatest downfall ofmany young rocket builders. With the incredible speeds andfrightful acceleration generated at launch, many fins get rippedoff the rocket body within a fraction of a second. I will discussthe reasons for this later, but for now let's list some commonbuilding materials
10Materials: (remember lightweight but sturdy) Index cards Clear packing tape, or duct tape Cardboard (cheap, plentiful, soggy when wet) Chipboard (cereal boxes) Foam core (a little tougher but more $, some water damage) Sturdy-board (like plastic cardboard, great stuff, $$, no water damage) Balsa wood (might be a little heavy, fragile on impact)
11How many fins do I need?To ensure stability and safety, the minimum number offins on a rocket is three (3). Many people choose a 3 or 4 findesign. There is no maximum number of fins you may havebut keep in mind that the more fins you have the more dragyou will create and drag slows a rocket down.
12Constructing fins 1. Be creative and cut out 3 or 4 identical fins. You can use any shape except "forward swept"fins. 2. Lay the fin on a flat surface. 3. Glue and/or tape an index card onto the sideof the fin. Be sure to leave a one-inch tab on theindex card.You will later bend this tab out 90 degrees tomake an attachable area for the rocket. 4. Repeat the same for the other side of the fin. 5. Repeat with other fins.You should now have 3 or 4 fins each with two-index card tabs on thebackside. (I like to laminate the entire fin surface with clear packingtape to reduce the amount of water damage to my cardboard fins.)
13Fin placementThe fins of your rocket can't be placed above the halfwaypoint of your pressure cylinder. You want to place your finsat the base of the rocket to lower or maintain the center ofgravity. If you were to place the fins above the center ofgravity, the rocket would tumble and spin out of controlonce it left the launch pad.
14Attaching the fins Apply a piece of tape to the index card tabs and them carefully tape them to your rocket.2. Look at your fin. Make sure it doesn't curveor it isn't crooked. It should be in a direct line with thebody of your rocket. If it isn't perfect, take it offand try again. 3. Attach the other fins. If you are using 4 finsthey should be at 90-degree angles. 3 fins shouldbe at 120-degree angles. 4. Test the wiggle of the fins. Your finsshouldn't wiggle more than a few centimetersfrom side to side. Adding more tape to the topand bottom areas of the fin might fix this problem.
18YOUR GROUP LAB REPORTYour group needs to write one lab report, so findsomeone who will be a good scribe. I suggest that youkeep the report in the “In box” so if the scribe is absent,the group can continue and have someone else write.Make sure that the name of everyone in your group ison the report. You will be graded by the quality of thereport, so make sure everyone in the group is happy withthe report.The report should have the following information:
19PURPOSE The purpose for this investigation is to construct a water bottle rocket that will travel the farthest distance down thefootball field.
20Variables Independent variable is the one thing you are testing In your experiment, remember to test only ONE newthing at a time! Testing more than one variable at atime makes it so you can’t tell if the outcome is becauseof one, the other, or both changed variables.
21Variables Dependent variable is the data measured as a result of testing the independent variable. In this case it will bethe distance traveled down the football field.Controlled variables: Everything that you are keeping thesame and not changing. Write down what you are keepingthe same such as: same pressure (all launches will be at60 psi) same launch angle, same fins or same nosecone,or same amount of water, etc.
22PROCEDURE Write down what you are using (aluminum foil, cardboard, tape, clay, posterboard, etc.) and how you’reusing all the stuff. Drawing pictures and labeling themis a really great idea.Then go test your ideas.
23DATA How did it go? What distance did it go? (make sure you include units of feet, meters, yards, etc). Writedown everything that happened and what youobserved, such as:how did it fly (straight, crooked, etc), did parts fall off,how did it come down, how did it land, etc.You will also need to include the following calculations:Solve for height: 4.9((ave. time)/2))22) Solve for initial velocity: V0 =(∆x/(∆t cos 45º))
24MODIFY PROCEDUREThis investigation is a series of loops. Using what you learnedon your first attempt, “tweak” it (make adjustments) and test itagain, or try something entirely different, but only change onevariable at a time. If you change the nosecone, keep the samefins water amount, and body style etc. If you decide to “tweak”or change the fins, then keep the nosecone, body style and wateramounts the same, etc.Tell what you are doing to improve or change the independentvariable, and what you are keeping the same as before. Be specific.
25CONCLUSION Based on your launches, tell how the factor (or factors) you were testing affected the flight of the rocket, and whatdesign you found to work the best.