Warm-Up 4/26/17 Take notes on what I say is important. Your complete notes are your ticket to building a rocket. For safety reasons, you cannot build if you do not have notes on this presentation. This is for a grade. It will have a large impact on your overall grade in the class. As long as you are here, and you work hard, you will be just fine.

Rocket Project: Newton’s 3 Laws in 3D!

All Rocket construction is done in the classroom. The only student expense will be the cost of engines.

Home built, not bought You will be working either by yourself or with a partner. You will need a cardboard tube (think: TP tube/paper towel tube but longer). Short tube rockets tend to be very unstable/unpredictable !

Anatomy of a Rocket

Considerations: Friction (air resistance): More surface area = more resistance. Has to punch a bigger “hole” in the air. Think about tube diameter and fin size. Force = mass x acceleration. Just like your jet cars, MASS is critical. The greater the mass the greater the inertia! For every action, there is an equal and opposite reaction (= rocket’s thrust!)

The Engine Compartment Engine mount: Fixed. Paper clip (recommended). This goes through the index card, but ABOVE the engine and keeps the engine from popping out the top of your rocket! Poster board foam rings, glued to inside of rocket fuselage Wrapping paper tube Rocket engine wrapped in index card(s)**

Engine Selection More is not always better! Like your jet cars, you need to consider the mass of your rocket. Letter Code: Size of engine. We will use C, D or E engines You can buy F, and G engines but don’t. First Number = Burn time. Higher the number, longer the burn. Generally heavier rockets need longer burns. Second Number = Delay before chute pops** You DO NOT want your nose cone to pop off while the rocket is still traveling upward!! Your tube size may limit the size engine you use.

Warm-Up 4/27/17 SWBAT take notes on building rockets safely. 1st period will take the ELA test today. We will continue with notes tomorrow. 2nd and 3rd period will continue their notes today and tomorrow.

Examples of engines

Fin Design Fins are a must to provide stability and help ensure that the rocket flies along a straight path. Fins Parallel with fuselage = straight path Uneven fins (size or spacing)= create unbalanced forces  who knows where it might go! NOT GOOD. Notice that the fins extend BELOW the level of the rocket 3 or 4 fins. 3 fins = 360 /3 =120 degrees apart 4 fins: 90 degrees apart

All fins will be made from foam board. No card board is permitted. FIN MATERIAL All fins will be made from foam board. No card board is permitted.

Which fins would not be ok to use?

Place tape on exposed edges but not on the side that attaches to the rocket.

Nose Cone This is what “punches” the hole through the air. Think bullet shaped to minimize air resistance. You may use the plastic eggs. Others carve out of balsa wood, or use a dixie cup. It needs to have a shock cord to keep it attached to the fuselage* Should fit snugly but not too tightly since it needs to pop off to let your parachute deploy

Parachute/Shock Cord String or rubber works ok. Should be anchored/glued to inside of body and tied to nose cone and chute material. This is what holds the chute to the rocket at deployment. You don’t want your chute (plastic bags or streamers work fine) to deploy too harshly or it will rip apart from your tube, then your rocket goes SPLAT! Recovery wadding: Tissue or some other light, soft material. Prevents your chute from burning up when the chute charge pops.

Rocket Stability Stability: there are two primary factors which influence the flight stability of a model rocket. Center of gravity: the point at which the rocket balances, should be determined with the full weight of the rocket Center of pressure: the theoretical point at which all forces directed against the rocket would center.

Rocket Stability If the center of gravity is located above the center of pressure, the rocket will return to its initial flight conditions if it is disturbed. Engineers call this a restoring force because the forces "restore" the vehicle to its initial condition and the rocket is said to be stable. Such a flight condition is shown on the left of the figure. https://www.youtube.com/watch?v=jqNbRm5xeqY https://spaceflightsystems.grc.nasa.gov/education/rocket/rktcp.html

Final step will involve painting Final step will involve painting. REMEMBER You may not carry spray paint to school

Rules If all you need to do is paint, you can fly without paint, but having painted is part of your grade If you still need to insert the engine block, see me after school TODAY Do NOT chase rockets! ONE person should be designated rocket retriever Do NOT go in the dug out, stay behind the back stop Leave the area cleaner than you found it, take your engines, or I will assume you are donations to the class

Lets finish up our notes with the model rocket guide. This document is posted next to this power point on the class website.

Work Day 4/28/17: Draw design, get body tube, report measurements for fins and body on design. 5/1/17: Draw lines of body tube, start cutting fins. 5/2/17: Finish fins, tape fins, begin attaching fins. 5/3/17: Attach fins 5/4/17: Finish attaching fins, attach sleeve to nose cone, attach shock cord 5/5/17: substitute, 1st period will use this day to do the reflection for the ELA test over 118 vocab words 5/8/17: Cut rings for engine compartment, assemble engine compartment. 5/9/17: Catch up 5/10/17: Have Mrs. Boss check engine compartment, then glue it together to dry, you will insert the engine tomorrow. (flap above paper clip needs glue too) Make parachute and streamers 5/11/17: Insert engine. Begin spray painting. 5/12/17: Finish painting. IF YOU HAVE YOUR ENGINES, GIVE THEM TO ME.