An Educator's Reference Desk Lesson Plan
Date: June 4, 1998
Grade Level(s): 6, 7, 8
Subject(s):
Objectives:
Students will attempt to:
Overview:
This lesson works well at the end of a solar system unit towards the end of school and is especially good for a science fair project. The main reference is a booklet called "Rockets Away," published by the Ohio State University Cooperative Extension.
Materials:
Students take notes on the following: (2 one-hour class periods)
I. History
A. 1200 AD- Used in the Middle East. Called "Chinese Fire Arrows"
Made of tubes stuffed with gun powder that when ignited,
exploded and produced hot gasses that pushed the rockets into flight.
B. 1687, Sir Isaac Newton published a book of principles which have
become known as Newton's Laws of Motion.
C. Only since the 1700's, have rocket experimenters actually
understood the scientific principles behind the motion of rockets.
D. Rockets were used in the War of 1812, which inspired the Star Spangled Banner
II. Newton's Laws
A. First Law
Objects at rest will stay at rest, or objects in motion will stay in motion, unless
acted upon by an unbalanced force. (see page 6-7)
B. Second Law
The acceleration of an object is directly related to the force exerted on that
object and oppositely related to the mass of that object. (see page 8 )
C. Third Law
For every action, there is always an opposite and equal reaction. (see page 9)
III. Rocket Launch
A. For a rocket to lift off, force must be exerted. (First Law)
B. The rate (speed) will be determined by two things (Second Law)
1. The mass (weight) of the rocket
2. By the force produced by the fuel. (air and water)
C. The reaction, or motion, of the rocket away from the launch pad is equal to and
opposite from the thrust of the engine or nozzle. (Third Law)
IV. Questions people ask NASA scientists about rockets
A. Do rockets really fly?
B. If rocket engines burn oxygen, how do they work in space?
C. Why do rocket engines have nozzles?
D. Why are rockets so long?
E. If rockets don't fly, why do they have fins?
F. Why are rockets so stream-lined?
G. If rockets fly in space without interference form air and gravity, why must they still be balanced?
V. Answers
A. Rockets move without the need of atmosphere (air) (demonstration #5,6)
B. Rockets carry oxygen with them as part of their propellant. (solid fuel)
C. The purpose is to increase and direct the acceleration of gases as they leave. (demonstration # 7 and a water hose)
D. To control the rocket and give it a control system. (demonstration #8)
E. Rockets are stabilized by the effects of air moving over the fins which function as controls. (demonstration #9)
F. Friction from the atmosphere will slow the rocket down while it is moving, called drag and turbulence. (demonstration #10)
G. In order for a rocket to remain stable (balanced), the center of pressure and the center of gravity should be no closer than 1/2 the distance equal to the largest diameter of the body. (demonstration #11)
Assessment
Students take a short quiz and then do bottle launches as a demonstration and for collecting data. (2-3 one hour class periods)
1. A rocket has a nozzle at the bottom of it where gasses escape pushing the rocket in the
opposite direction with an equal amount of force. This is an example of Newton's _____Law.
2. A rocket sitting motionless on a launch pad will stay motionless until the engine ignites. Once
it is moving, it will continue to move until another force stops it.
This is an example of Newton's____ Law.
3. The acceleration or speed of the rocket depends upon how heavy
the rocket is and how much force is used to lift the rocket.
This would be an example of Newton's _____law.
4. True or False?
A one pound brick will fall about 32 feet per second and a ten pound brick
would probably fall about ten times faster (320 feet per second) since it is ten times heavier.
5. True or False?
Rockets were first used by the Chinese in the War of 1812 which inspired
Francis Scott Key to write the Star Spangled Banner.
Using a spreadsheet program, make a
launch recording data chart
with the following titles:
| Launch # | Water (ml) | Air (psi) | Nose Wt. (g) | Total Wt. (g) | Time (sec) | Altitude | Velocity |
| 1a | |||||||
| 1b | |||||||
| 1c | |||||||
| 2a | |||||||
| 2b | |||||||
| 2c | |||||||
| 3a | |||||||
| 3b | |||||||
| 3c | |||||||
| 4a | |||||||
| 4b |
Number eleven plain 2 liter bottles in the following manner:
1a, 1b, 1c, 2a, 2b, 2c, 3a, 3b, 3c, 4a, 4b
and enter them onto the launch data sheet.
Bottles numbered 1a, b, c get launched with 0 ml water, 0 nose wt., and 40, 60, 80 psi. air.
Bottles numbered 2a, b, c get launched with 500ml of water, 0 nose wt., and 40, 60, 80 psi. air.
Bottles numbered 3a, b, c get launched with 750 ml of water, 0 nose wt., and 40, 60, 80 psi. air.
Bottles numbered 4a, b get launched with 500 ml of water, 60 psi air, and nose wt. of 80 grams and 160 grams.
Launch the bottles and record the times from blast off until they hit the ground.
As a class, calculate the altitude and velocity of the first two or three launches using the appropriate formulas.
Assign the rest of the launches to pairs of students. On an overhead, make a double line graph to compare the height with the air and water amounts.
H= (t/2) squared x16
V= H /(t/2) fps multiply by .68 to convert it to mph.
Students begin building rockets (2 one hour class periods)
Follow guidelines in booklet to construct fins and attachment to bottles.
Use recorded data to decide which weight, air, water ratio's work best.
Launching. (about 20 launches in an hour)
Allow students to launch at least twice changing only one variable at a time.
Record the times and let students calculate the height and velocity as well as complete a graph of their launches.
Take a final test on the unit. Extra grades can be taken from several things such as calculations, graphs, following directions for building, etc.
A final competition can be held for one launch of their favorite design.
Students have come up with wing designs, length variations, paint and glitter, etc.
Winner gets an Estes model rocket.