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 be working either by yourself or with a partner. You will need a cardboard tube (think: TP tube/paper towel tube but longer). You will need a cardboard tube (think: TP tube/paper towel tube but longer). Short tube rockets tend to be very unstable/unpredictable ! 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. 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! 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!) For every action, there is an equal and opposite reaction (= rocket’s thrust!)

The Engine Compartment Poster board foam rings, glued to inside of rocket fuselage Rocket engine wrapped in index card(s)** 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! Wrapping paper tube

Engine Selection More is not always better! More is not always better! Like your jet cars, you need to consider the mass of your rocket. Like your jet cars, you need to consider the mass of your rocket. Letter Code: Size of engine. Letter Code: Size of engine. We will use C, D or E engines We will use C, D or E engines You can buy F, and G engines but don’t. 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.

Examples of engines

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

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

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. 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* 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 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.

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