It’s not rocket science….oh, actually it is! J
Name:______Partner’s Name:______Block:______
Objective:
You and a partner (optional) will create one bottle rocket that will fly straight and remain aloft for a maximum amount of time. You will use a simulation program to design your rocket and estimate the height. You will then construct your rocket to the specifications, launch it, and record the height. A short lab report and summary, along with a schematic of your rocket, will be required to complete this lab activity.
Assignment
Part 1: Decide on partner.
Part 2: Pre-lab: Simulate your rocket on the computer. Print/send simulation prototype. Build your rocket. Draw a blueprint for your rocket. Answer pre lab questions.
Part 3: Lab: Launch rocket and record data.
Part 4: Post –lab: Data Analysis. Calculate height. Answer questions.
Due Dates:
Part 1: ______
Part 2: ______
Part 3: ______
Part 4: ______
Part 1: Simulating your rocket
Go to the following link: http://exploration.grc.nasa.gov/education/rocket/BottleRocket/RM2.html
This program can be a little confusing so here is a crash course:
Step 1: Design
Begin by selecting WATER from the types of rockets available. You will start on the BODY section of the DESIGN menu. Here you can add or remove the body fairing. The fairing is a cylindrical segment that covers the curve of the bottle from the top to the nozzle. It can help reduce air resistance. If you do not want a fairing, select NO FAIRING. Your fairing should not extend past the bottle's nozzle. Don't change the drag coefficient.
Next, go to the FINS section. Your fins cannot extend very far past the nozzle. You will have to move them up. They cannot go too high, though, because the rocket will become unstable. You can select the shape as trapezoid or cylindrical, and alter the shape using the sliders. Keep note of the dimensions of your fins!
After that, head to the PAYLOAD section. Here you can alter the length of your rocket. You will add a payload to the top of your rocket (the bottom of the bottle) by using a second bottle and cutting it to suit your needs. The additional payload length shouldn't be more than 6 inches.
Lastly, go to the NOSE section to design your nose. If you plan on making a nose out of poster, select hollow cardboard. If you are going to use only the top of the 2nd bottle for the nose, select hollow plastic. You can add mass to the nose cone using the BALLAST control. Note that the center of gravity changes as you do this. You want to have the center of gravity above the center of pressure!
When finished designing, click GO, then head over to the fuel section. If the design button turns RED when you click fuel, then you have a major flaw and your rocket will be too unstable to launch...you'll have to find and fix the error, or restart (by clicking WATER again).
Step 2: Adding Fuel.
Here, you will add water and pressure to your rocket. The volume is in cubic inches...I would suggest clicking the metric scale in the top right corner and adding water in cc (which is equal to mL). Once you have your water added, set the pressure to 60 psi (in English). Everyone MUST use 60 psi as their pressure setting. The launch tube is about an inch in length, and the diameter can be set to about .7 in. When you're done fueling up, click GO and head to the PAD section.
Step 3: Setting up the launch pad.
Don't change anything here except length of the launch rail. Set it to 1 ft. Click GO, and if all of the other buttons are green, you're ready to launch.
Step 4: Launch!
When ready, hit the FIRE! Button to launch your prototype after a brief countdown. Take note of the height. Head back to the drawing board to change your rocket design, and relaunch. Repeat this process until you are satisfied with your rocket, then record the information needed from the launch page.
Simulator Launch Data:
Maximum Height / ______ft ______mTime of Flight / s
Amount of water / ______mL or ______L
Step 5: Saving your prototype
When you are finished, go to the FUEL section, and hit the PrintScreen button. This will take screen shot of the display. Paste it into word, and save it as a JPEG file. Do the same thing on the LAUNCH section BEFORE launch, and again AFTER launch. You should have 3 images. Save them in a folder with your name and block. You may print or email the file to me () by ______.
Before you close the simulator, make sure to write down any dimensions that you will need to build your rocket (such has fin length/width, cone length/diameter, etc).
You're now ready to begin building your rocket!
Part 2: Building your Rocket!
Now that you have your design, it’s time to build your rocket. You will use cardboard for your fins, and poster board for your nose cone. The two bottles you will have will become your nose cone. One will stay whole, and the other will become the payload (top portion) of your rocket, where you can add mass to shift the center of gravity.
Guidelines:
1. Rockets are to be constructed from 2 –liter soda bottles.
2. The bottles must be plastic, no glass or breakable materials may be used. No sharp instruments!
3. No explosives/ chemicals allowed.
4. The rocket must remain intact during the launch – this includes the bottle, fins, nose cones, etc. Points will be deducted if the rocket comes apart. No hot glue or super glue.
5. Your fins must be identical, and symmetrical. If they aren’t, your rocket will be unstable and will lose height.
6. Your fins cannot be too high on the rocket, and they cannot extend too far past the nozzle of the bottle.
7. Consider ways to reduce drag (air friction) on your rocket.
8. The rocket should have a high center of mass and a low center of pressure.
9. Ideas to increase mass – tennis ball, play dough, duct tape, etc. Cannot be breakable!
10. Other materials to consider using – manila folders, lightweight wood, duct tape, clay, cold glue.
Rocket Blueprint
You and your partner must complete a blueprint of your rocket. This blueprint should accurately depict your rocket. Use rulers and other drawing aids to produce a neat blueprint. Feel free to name your rocket!
The blueprint should show the following:
1. Parts of rocket are labeled (nose cone, fins, where you will put the water, pressurized body, etc)
2. Size of the fins
3. Length of your rocket
4. Total mass of the rocket (without water)
5. Maximum height attained (after launch, of course)
Part 3: Launch Day!
On the day of launch, you will fill your rocket with the amount of water you specified, and pressurize it to about 40psi. Safety goggles are REQUIRED for everyone – these rockets launch at high velocities, and can cause serious injury if you’re struck in the face.
Part 4: Rocket Science:
1. Finding maximum height – projectile height equation.
The equation h=0.122g(t)2 will give you a very good approximation for the height of your rocket. Because the water will be expelled very quickly, the rocket becomes a projectile almost immediately. The only thing you need to measure is the time required for the entire flight of the rocket. Use a stopwatch to find this. Start it when the rocket launches, and stop it when it hits the ground.
Prelab Questions
1. Why do bottle rockets fly?
2. Why do we have to use water?
3. Will it fly without water?
4. What safety procedures do we need to follow?
5. State Newton’s three laws of motion:
6. Define potential and kinetic energy: