Principles of Rocketry. Isaac Newton's 3 rd law of Motion For every action there is an equal and opposite reaction For every action there is an equal.

Principles of Rocketry

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 Fuel in solid form burns and is converted to hot gassesconverted to hot gasses Hot gasses expand and create high Hot gasses expand and create high pressure pressure

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

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

Equal pressure in all directions

Nozzle

Gasses Rocket

Solid FuelBurning fuel Producing hot gasses

Hot gasses escaping

Action Reaction

Pascal’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 Instead of hot gasses creating pressure, we use a bike pump and pressure, we use a bike pump and store pressurestore 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 Reaction: Water resisting against rocket body. rocket 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 Water Rockets Work Like Real RocketsLike Real Rockets

Other factors that make the Water Bottle Rocket Fly Compressed 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

• #1An object will stay at rest unless a force acts upon it.

• #2Force = Mass x Acceleration

• #3For 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 100mLs

Too 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 Stability During Flight….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

Bring These Materials to class on Monday

• Two, 2-Liter soda bottles

• Old cd’s

• Duct Tape

• Manila envelopes

• Clay

• Stickers, paint, colorful duct tape for prettiness and other decorations are optional

Lesson by Mr. Alex Sowyrda Cooperating Teacher: Mr. Robert

Jones Kenney Middle School 7th Grade

Technology Hannibal, NY Sept – Oct 2004

• http://www.hannibal.cnyric.org/TeacherWebs/Rjones/rockets/PowerPoint/Rocketry_files/frame.htm