Transcript How Rockets Work

How Rockets Work
With a little history thrown in for fun
Hero Engine
~100 BC
Chinese Rockets - “Fire Arrows”
in Military Use ~1200 AD
First Manned Rocket?
Isaac Newton
• 1687
• Laws of Motion
• Paved way for modern
rocketry
Robert Goddard
First Liquid Fueled
Rocket
German
Scientists
Develop Long
Range Missiles
during World
War II
Newton’s Laws of Motion
• In the absence of net external force, objects
tend to maintain their state of motion
• Acceleration is directly proportional to
force applied and inversely proportional to
mass
• For every action force, there is an equal but
opposite reaction force
In the absence of net external force,
objects tend to maintain their state of
motion
• If nothing pushes or pulls
– Objects at rest, stay at rest
– Objects in motion move in a straight line with
constant speed
Acceleration is directly proportional to
force applied and inversely proportional to
mass
• If you push harder
– The motion changes faster
• If the object is heavier
– You must push harder to get the same change in
motion
For every action force, there is an equal
but opposite reaction force
• Forces come in pairs
• When an object can’t push back any harder, it
moves away to lessen the push it is getting
He pushes the rock
The rock pushes back
Applied to Rockets
• The rocket will stay where it
is until the engines ignite.
The rocket will keep moving
when the engines stop.
• More mass requires bigger
engines
• Gasses are pushed
backward by the rocket
(action) the rocket is
pushed forward by the
gasses (reaction)