Mmm....ELab

Jordan Derkachenko Kyle Bonilla Matt Rae November 15, 2011 Physics 30, Period 5 __** Rocket Launch 2011 **__ __**Purpose:**__ The purpose of this project is to examine some of the major concepts that we have studied in Physics 30 through the use of a model rocket.


 * __Materials:__**
 * Mailing Tube
 * Balsa Wood
 * Dime Roller
 * Elastics
 * Fishing Line
 * Duct Tape
 * Masking Tape
 * Paint (Orange, Blue, Black, White)
 * Paper
 * Gorilla Glue (Super Glue)
 * Styrene Plastic
 * Heavy Paper Clips
 * Straw
 * Rocket Engine
 * Rocket Engine Igniter
 * Rocket Engine Plug
 * Coat Hanger
 * Sandpaper (80g)

__**Procedure:**__ 1) Create body tube by cutting mailing tube down to size (31.8cm) using a bandsaw 2) Create engine mount out of paperclip, dime roller and masking tape as seen in Diagram 2 3) Cut out four identical fins from styrene see Diagram 1 for specifications 4) Shape nosecone with 80 grit sandpaper so that it fits snugly into the top of the body tube (make it so it can be pushed in approx 0.5cm and is 8cm in length) 5) Attach fins to body of rocket as seen in Diagram 1 so that the bottom of the side attached to the body is level with the bottom of the tube and so that the fins are equally spaced and parallel to the sides of the body 6) Create spacers for the engine mount by cutting out two pieces of styrene the shape and circumference of the bottom of the body tube, tracing the engine mount into the centre of the pieces, then cutting out the traced shape, being careful not to cut into the side of the spacers. Attach the spacers approx 0.5 cm in on either side of the mount with super glue. 7) Super glue engine mount into the bottom of the rocket, leaving a small amount of the mount sticking out the end of the rocket to allow for easy ignition. Optional: reinforce with paperclips and/or duct tape 8) Cut out 4 (25cm by 3.2cm) rectangles out of styrene for the helicopter blades and fold all of them slightly down their length so that they make a shallow "v" shape at the ends. Make sure the fold is equal down the entire length and that all four of the folds are equal 9) Duct tape the blades 2 cm up from the bottom of the nosecone and equal distance from each other so that the open end of the "v" is facing down and half of the folded blade is parallel to the bottom of the nosecone, leaving the other side to jut down at an angle. Make the taping as unobtrusive to the overall shape as possible (see Diagram 3) 10) Measure out four equal lengths of fishing line ( around 12 cm will work). Tape one end of each length of fishing line to the bottom of the nosecone so that they directly line up with the fold line of each blade. Poke a hole in each blade 8 cm away from the connection with the nosecone (a hot needle works well). Poke the fishing line through the hole of its respective blade and take up the slack until the blade is restricted to a maximum angle of 70 degrees with the side of the rocket. Use duct tape and super glue to attach the line. 11) Cut out a 37cm length of line and attach a paper "packet" at each end by folding the line up in a piece of paper and gluing it all together. 12) Glue one packet to the inside of the body tube and the other to the bottom of the nosecone. 13) Glue a straw to the corner made by one of the fins and the body tube. This will be what attaches the rocket to the guide pole on the launch pad. 14) Place nosecone in top of body tube. 15) Place elastic band over the very bottom of the helicopter blades around the body tube. This will hold them in until the charge goes off 1) Place C-6-3 engine in engine mount. 2) Place igniter and plug into bottom of engine 3) Slide the guide pole of the launch pad through the straw affixed to the rocket 4) Attach launch control device to igniter 5) Press button __**Data: (Launch 2)**__
 * Launching: (see Diagram 4)**
 * __**Data**__ || **__Value__** ||
 * Pre-Launch Mass || 195.87g ||
 * Post-Launch Mass || 182.3g ||
 * Angle of Elevation || 18 degrees ||
 * Time Up || 3 seconds (approx) ||
 * Time Down || 4 seconds (approx) ||


 * Launch || Time Up || Time Down || Angle of Elevation || Controlled || Takeoff || Recovery || Broken Parts ||
 * 1 || 4.62s (time up and down combined) || - || 14 Degrees || Yes || Yes || No || Yes (bad) ||
 * 2 || 3s || 4s || 18 Degrees || Yes || Yes || Yes || Yes (bad) ||

__**Analysis:**__ tan18= __x__ 100
 * 1)** Pre-Burn mass: **195.87g**, Post-Burn mass: **182.3g**
 * 2)** Compute the height from trigonometry ( need distance of observer away from launch site and the angle of the launch). (see Diagram 5)
 * Height (x) = 32.49 m**

up - 3 sec down - 4 sec V = __32.29 m__ V = __32.29 m__ ..........3................. 4.....
 * 3)** Compute average velocity up and average velocity down (Using height from #2 and measured times up and down).
 * V = 10 m/s V = 8 m/s**

__**a) Thrust Phase: F-net=ma=F-air+F-g+F-a**__
 * 4)** Force analysis

//F-net=ma// 32.49m= 0 + 1/2 a (3s)^2 32.49m/4.5(s^2) = a
 * a= 7.22m/s^2**

m= (195.87g+182.3g)/2
 * m=189.085g or 0.189kg**

F-net = (0.189kg)(7.22m/s^2)
 * F-net= 1.36N**

//1.36N=F-air + F-g + F-a//

1.36N=F-air +(-1.9N) + 6N 1.36N=F-air + 4.1N //__**1.36N=(0.189kg)(7.22m/s^2)= (-2.71N)+(-1.9N)+(6N)**__// __**b) Descent Phase: F-net=ma=F-air+F-g**__
 * [F-g= (0.196)(-9.8)**
 * = -1.9N]**
 * [F-a= 6N (engine specs)]**
 * F-air =-2.74N**

F-net= (0.182g)(0m/s^2)
 * F-net=0**

//0= F-air + F-g//

F-g= (0.182kg)(-9.8m/s^2)
 * F-g = -1.8N**

0= F-air + (-1.8N) F-air= 1.8N

Constant Velocity: //V-avg=d/t// v-avg = (32.49m)/(4s) //__**v-avg = 8 m/s**__//

__**Sources of Error:**__
 * Wind
 * Differences in air density and pressure
 * Differences in engine thrust/timing
 * Imperfections in the materials
 * Gravity value used was an average, not an exact calculation
 * Flight times up and down were only accurate to the second (had to use video from the launch)

__**Conclusion:**__ Through the building of our model rocket, we learned how to apply the laws of Kinematics and Newton's Laws to real life situations by finding the average velocity of our rocket (10m/s up, 8m/s down) and the net forces acting on it during its flight (1.36N up, 0N down). We also got a chance to see constant motion and terminal velocity by studying our rockets descent. Although we were unable to obtain a completely successful launch, we learned valuable problem solving skills and got a chance to grasp many important concepts like aerodynamics, propulsion and drag that can be tricky to learn about in a classroom setting. We also got a chance to improve our teamwork skills.

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