Principles of Rocketry

Bring These Materials to class on Monday 9/30/13

• 1 2-Liter soda bottle• Duct Tape• Manila envelopes or cardboard• Stickers, paint, colorful duct tape for

unique designs and other decorations are optional

Isaac Newton's Isaac Newton's 33rdrd law of Motion law of Motion

For every action there For every action there is an equal and is an equal and opposite reactionopposite reaction

                                                                                                              

                               

What is the Action?What is the Action? Solid Fuel Rockets Solid Fuel Rockets

Fuel in solid form burns and is converted to hot gassesFuel in solid form burns and is converted to hot gasses

Hot gasses expand and create high pressure Hot gasses expand and create high pressure

Pressure escapes out nozzle, pushing against air and Pressure escapes out nozzle, pushing against air and rocket body equally rocket body equally

- Reaction: - Reaction: Rocket moves forward, as Rocket moves forward, as gasses move backwardsgasses move backwards

Equal pressure in all directions

Nozzle

Gasses Rocket

Solid Fuel

Burning fuel Producing hot gasses

Hot gasses escaping

Action ReactionPascal’s Principle

DRAW THE ROCKET

Space Shuttle:Space Shuttle:Solid and Liquid Fuel RocketsSolid and Liquid Fuel Rockets

Solid Fuel Rocket Boosters

Liquid Fuel and Oxygen tank Feeding Engines

Our Water RocketsOur Water RocketsInstead of hot gasses creating pressure, we Instead of hot gasses creating pressure, we use a bike pump and store pressureuse a bike pump and store pressure

Action: Expelling water from engine bottle. Action: Expelling water from engine bottle.

(water is forced down) (water is forced down)

Reaction: Water resisting against rocket Reaction: Water resisting against rocket body. body.

(Rocket is forced up)(Rocket is forced up)

High Air pressure is transmitted equally in all directions and parts of the fluid.

Water forced out and down by air pressure

Action:

Reaction: Bottle forced up by water being expelled down

Pascal’s Principle

Water Rockets Work Like Real Water Rockets Work Like Real RocketsRockets

Other factors that make the Water Bottle Rocket FlyCompressed Air + Water

WRITE

WRITE

WRITE

When you pull the pin on the launch pad, and the latch holding your rocket to the launch pad pulls back, no force will be holding that rocket down! The unbalanced force of the High air pressure inside of your rocket will instantly rush out of the rocket nozzle pushing your rocket into the sky!

Mother Nature doesn't like it when things aren't equal!

Newton's 3 Laws Explains Everything

Newton's 3 Laws of Motion• #1 An object will stay at rest unless a

force acts upon it.

• #2 Force = Mass x Acceleration

• #3 For every action there is an equal an opposite reaction.

How Newton's Laws Affect Our Rockets

• Newton's First Law

When you pressurize your rocket and compress all of that air into your rocket engine, the force of the launch pad latch equals the force of the compressed air. Your rocket is resting, it will go nowhere.

Newton's Second Law

This law tells you how much force (push) is going to come out of your rocket nozzle. The air is the accelerant, the water is the mass. You are limited to a 2000 ml volume rocket engine (a 2 liter pop bottle).What ratio of compressed air (limited to 65 psi) and water (your choice) will produce the most force?

About half the bottle full of water 100mLsToo much mass = too much inertia No mass = nothing to push off of

Newton's Third Law

• When you pull the pin, that area of High Air Pressure in the top of your rocket engine is going to force, throw, hurl, spew that "massive" water out the bottom of your rocket at a great speed. That water and air is pushing down, so your rocket must go up.

Stability During FlightStability During Flight

Center of Gravity Center of Pressure

The orientation of fins and distribution of mass help make the rocket stable.

Center of Gravity

Stability During Flight….Stability During Flight….

Think about a dart….

Fins or feathers in the rear act like wind veins and trail behind

Heavy mass in front carries the momentum

David L. Pop Bottle Rocket video

Bring These Materials to class on Monday 9/30/13

• 1 2-Liter soda bottle• Duct Tape• Manila envelopes or cardboard• Stickers, paint, colorful duct tape for

unique designs and other decorations are optional