Principles of Rocketry

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Principles of Rocketry
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Our Water Rockets

• Instead of hot gasses creating pressure, we use a
  bike pump and store pressure

Action Expelling water from engine bottle.
(water is forced down)
Reaction Water resisting against rocket body.
(Rocket is forced up)
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Water Rockets Work Like Real Rockets
DRAW THE ROCKET AND WRITE EVERYTHING DOWN
Pascals Principle
Reaction Bottle forced up by water being
expelled down
High Air pressure is transmitted equally in all
directions and parts of the fluid.
Action
Water forced out and down by air pressure
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Other factors that make the Water Bottle Rocket
Fly
Compressed Air Water
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How Newton's Laws Affect Our Rockets
WRITE THIS

• Newton's First Law

The pressure inside the rocket must overcome the
INERTIA of the rockets weight to launch. If the
rocket has too much water, it will have too much
weight/INERTIA.
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Newton's Second Law

• This is why you need just the right mass and
  force to achieve a good acceleration

80psi is perfect for 275-350g
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Newton's Third Law
DONT WRITE WHATS IN YELLOW

• 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 (action
  force), so your rocket must go up (reaction
  force).

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Stability During Flight
The orientation of fins and distribution of mass
help make the rocket stable.
Center of Gravity
Center of Pressure
WRITE THIS DOWN
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Gasses Rocket
Action
Reaction
Equal pressure in all directions
Pascals Principle
Hot gasses escaping
Nozzle
Burning fuel Producing hot gasses
Solid Fuel
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Isaac Newton's 3rd law of Motion

• For every action there is an equal and opposite
  reaction

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Stability During Flight.
Think about a dart.
WRITE THIS DOWN
Fins or feathers in the rear act like wind veins
and trail behind
Heavy mass in front carries the momentum
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What is the Action?
Solid Fuel Rockets

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

• Hot gasses expand and create high pressure

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

- Reaction Rocket moves forward, as gasses move
backwards
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Space ShuttleSolid and Liquid Fuel Rockets
Liquid Fuel and Oxygen tank Feeding Engines

Solid Fuel Rocket Boosters
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DONT WRITE WHATS IN YELLOW
Mother Nature doesn't like it when things aren't
equal!
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!
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Newton's 3 Laws Explains Everything
DONT WRITE THIS

• 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.

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Center of Gravity
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Bring These Materials to class on Monday

• Two, 2-Liter soda bottles
• Old cds
• Duct Tape
• Manila envelopes
• Clay
• Stickers, paint, colorful duct tape for
  prettiness and other decorations are optional

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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