Intro Physics (Each individual student will complete his or her own lab report)

Transcription

1 Intro Physics May/June 2016 Name (Each individual student will complete his or her own lab report) Bottle Rocket Lab - Target Launch Date: Group Members: Post Prototype Launch questions (max 8 points) Due date: Questions worth 2 points each based on accuracy and completeness Pre Launch questions (max 32 points) - Due date: launch date Questions 1-16 are worth 2 point each, (1 point for accuracy and 1 point for completeness) Challenge questions are worth 1 point each, based on effort and thought Construction and Design reflection (max 9 points) - Due date: launch date Content: 1 st paragraph: prototype round (3 points) o Explain your design o Include a labeled diagram of your design o Explains how the prototype performed Content: 2 nd paragraph: design (3 points) o Explain your design o o Include a labeled diagram of your design Explain how you implemented any improvements after the prototype round Format (3 points) o Make sure it is typed (all but the 2 diagrams) o Properly formatted (line spacing, font type, font size, proper diagrams) o Includes a title (other than the word TITLE) in bigger font and you name, block, and date Performance (max 9 points) You get 3 points for attaining each of the following: Looks like a rocket Launches Flies true (doesn t tumble or go out of control) Post Launch questions (max 8 points) Due date: Monday 6/15 Questions worth 2 points each based on accuracy and completeness In class work and focus (1 points each day) Max. 6 points When you work on the project make sure you: Stay focus in class (teacher doesn t have to call your attention to stay on task) Bring all necessary materials for the completion of the project Teacher will mark this rubric by the end of each day to take one or two points off if you need to improve record Day 1 research and build prototype rocket 1 Day 2 launch prototype and work on hand out 1 Day 3 work on hand out Day 4 build second and final rocket 1 Day 5 launch second and final rocket 1 1 Total : /

2 Water Rockets In 1919 Robert Goddard, a professor at Clark University in Worcester, Massachusetts, claimed that a multistage rocket weighing only ten tons could land on the Moon. After years of research, Goddard built the first liquid-fueled rocket, achieving a height of 90 feet before angry neighbors and local police ordered him to cease rocket experiments in Massachusetts. He moved to New Mexico where he continued his pioneering work in rocketry. It is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow -- Robert H. Goddard NASA The Introductory Physics students at NNHS are going to revive the Massachusetts tradition of rocket innovation by building and launching our own low-tech rockets, using 2-liter plastic soda bottles, cardboard, and water. We will use a bicycle pump rocket launcher and release the rockets in one of the fields outside.

3 Bottle Rocket Construction Procedure Materials (please bring plastic 2 liter soda bottles to school) One 2 liter bottle (Two 2-liter bottles if you are planning to make a taller rocket) Tape / glue Cardboard / poster board / manila folders Clay Optional for parachute (if you make a second rocket!) String Garbage Bag Rubber Bands Balloon Procedure (look at the diagram in the previous page) 1. Cut out nose cone from cardboard. Place a small handful of clay into tip of nose to vary the location of the center of mass. 2. Cut and tape fins onto nozzle end of bottle. Shape and orient the fins so that they will increase aerodynamic stability. 3. Optional: Using the top, bottom, or a cylindrical section of your second 2-liter bottle to make your rocket longer. Make sure you attach this extra part to the bottom of the intact bottle, leaving the opening of the intact bottle free (this will be used to pump air inside and pressurize the rocket) 4. Optional: Create an extra compartment for a parachute under the nosecone. Attach the nosecone with a string. As you build the rocket, be sure that the center of mass is above the center of pressure.

4 Bottle Rocket Pre Launch Questions: These questions should be answered before the launch day, individually. When Robert Goddard proposed a rocket to the Moon in 1919, the New York Times ridiculed the idea, claiming that a rocket could not possibly propel itself through the vacuum of space: after the rocket quits our air and really starts on its longer journey it will neither be accelerated nor maintained by the explosion [Professor Goddard] does not know of the relation of action to reaction and the need to have something better than a vacuum against which to react [He] only seems to lack the knowledge ladled out daily in high schools. The New York Times, Define Newton s Third Law (N3L): 2. Explain how N3L applies to rockets. 3. Explain why Goddard was correct and the New York Times was wrong.

5 4. Consider the following diagram of a V-2 rocket. Each part of the rocket has a specific function. The nose cone reduces drag. The fins add stability. Answer: what is the function of the propulsion system? 5. Draw the direction that the net force points in each part of the trajectory. Remember that net force implies acceleration: net force and motion in the same direction, motion speeds up; net force and motion in opposite directions, motion slows down.

6 6. Draw a free body diagram of the bottle rocket at each of the following stages: At rest on launch pad, during launch, coasting ascent (still rising, but rockets are no longer firing), maximum altitude, coasting descent (rocket is falling, rocket is not firing). At rest During launch (engine firing) Coasting ascent (engine no longer firing) Maximum Altitude Coasting descent 7. Describe the gravitational potential energy and kinetic energy changes at each part of the trajectory. (Example: GPE is increasing/decreasing/zero and KE is increasing/decreasing/zero) At rest During launch (engine firing) Coasting ascent (engine no longer firing) Maximum Altitude Coasting descent 8. Describe how high would the rocket go on the moon compared to earth and use CER to explain why.

7 9. Define Newton s 2 nd Law (N2L) here. 10. If you want your rocket to go as fast and high as possible (to attain the maximum possible acceleration), explain what design decisions you should make. Support your design choices with N2L. 11. State the law of conservation of momentum. 12. Define what is your system. 13. Based on the law of conservation of momentum, the momentum that the rocket attains is equal and opposite to the momentum of the escaping fluid. Explain why we can achieve greater speed using a combination of water and air as opposed to just air.

8 Use the Forces on a Rocket Diagram on the right to answer the next 2 questions: 14. Describe how changing the mass would affect the flight of the rocket. 15. If the forces on the rocket are balanced, state what acceleration will the rocket experience. Explain your reasoning using one of Newton s three laws of motion. 16. Explain: how can we tell if the forces are balanced once the rocket is in flight? Challenge questions - If you want to answer these questions, you may do some research (see resources in the next page) or get together with a classmate to work on them, but your answer must be your own and you must cite your sources. I will not answer them for you! 17. Describe how the rocket would fly without a nose cone. Use CER to explain your answer.

9 18. Describe how the rocket would fly without fins. Use CER to explain your answer. 19. Explain how the function of the fins and nose cone would be different on the moon. 20. If you measure the time the rocket is in the air and assuming you do not use any device to slow down the descent. Can you calculate the how high the rocket went? How? (Only the equation) What else would you need to know to be able to determine the height? References: Most of the NASA pictures in this handout are taken from: More information on water bottle rockets (not all these links work properly)

10 Intro Physics June/May 2015 Name (Each individual student will complete his or her own lab report) Bottle Rocket Lab: After launch Questions (due by the end of class) Group Members: 1. Describe in detail how your group s rocket performed. Was it able to lift off the ground? How high did it go? What trajectory did it follow? Did it maintain stability? 2. How did your rocket compare with rockets made by your classmates (in terms of lifting, height, trajectory, and stability)? Did your rocket perform better than the first round rocket? How did your rocket compare with rockets made by your classmates? 3. Describe the one or two rockets from your class that performed the best, and the one or two worst. In what ways were they different from the others? 4. How could you improve your rocket to make it travel higher and farther? What are some specific things you would change/alter?

11 Intro Physics June/May 2015 Name (Each individual student will complete his or her own lab report) PROTOTYPE Bottle Rocket Lab: After launch Questions (due by the end of class) Group Members: 1. Describe in detail how your group s rocket performed. Was it able to lift off the ground? How high did it go? What trajectory did it follow? Did it maintain stability? 2. How did your rocket compare with rockets made by your classmates (in terms of lifting, height, trajectory, and stability)? How did your rocket compare with rockets made by your classmates? 3. Describe the one or two rockets from your class that performed the best, and the one or two worst. In what ways were they different from the others? 4. How could you improve your rocket to make it travel higher and farther? What are some specific things you would change/alter?