PHYSICS PBL
Water Rocket
With Parachute
By the member of :
Chin Ze You
Cheong Qi Zhe
Chin Zhen Hung
Lai Cheng Feng
CONTENTS
1. Materials
2. Explanation of Design & Functionality
3. Safety Precaution
4. Concept of Science
PHOTOS
MATERIALS
Materials needed for rocket body
Soda bottle
Water
Funnel
Bicycle pump with pressure meter
Materials needed for fins and nose cone
Milk or Juice carton (emptied and cleaned)
Ruler
Scissors
Duct Tape
Permanent Marker
String
Materials needed for parachute
Plastic Bag
Ruler
Cotton string or fishing line
Scissors
Duct Tape
Explanation of design &
FUNCIONALITY
Octagonal Canopy
(Parachute) Nose Cone
Fins
Explanation of design &
FUNCIONALITY
1. Nose cone
a. the nose cone helps to reduce air drag by
streamlining the air as it flows past the
surface of the rocket
2. Fins
a. for increase aerodynamic stability
b. without fins, the rocket will not fly straight
3. Octagonal Canopy
a. this will slow down the aerodynamic from
lending
b. when the octagonal canopy opens, it will
trap the air which is going against it, it is
also known as air friction
CONCEPT OF SCIENCE
Water rocket works with the Principle of the Conservation of
Momentum. If objects collide, the total momentum before
the collision is the same as the total momentum after the
collision (no external force)
As the air is pumped into the bottle, the pressure inside the
bottle builds up the force of the air pushing on the water is
enough to force the cork out of the end of the bottle.
Adding a parachute increases the chance to recover the
rocket undamaged. The additional mass and the change in
the rocket's aerodynamics will slightly change the maximum
altitude the rocket can reach.
A bottle rocket does not have a parachute ejection system
like real rockets, so the air has to push off the nose cone,
allowing the suspension lines to unwind and the parachute to
unfold. This all needs to happen before the parachute
touches the ground.
The faster the water comes out (at higher acceleration), the
higher the rocket gets lifted. The more air you add, the more
this air pushes on the water.
Rockets are vehicles that obtain their forward thrust—the
force that pushes the rocket forward—from a reaction
engine. In other words, rockets push themselves forward by
ejecting mass (that shoots backward) at high speed from
their rear end.
SAFETY PRECAUTIONS
1. Do not leave two liter bottles in a hot car.
2. Only launch with adult supervision, in a wide
open field, far away from trees, buildings, roads,
people and electrical wires.
3. Never launch your rocket at or near people,
animals, automobiles, aircraft or buildings.
4. Don't put any more than the recommended
amount of water in any rocket bottle, or the rocket
may lift off sideways.
5. Don't rush a launch. It is always better to abort a
launch if there is a problem and try again later.
6. As you set up your rocket on the launch pad,
observers should stand back several meters. It is
recommended that you rope off the launch site.
