Model Rockets
PURPOSE
To investigate the principles of rocket flight. To build and launch a toy rocket, and to apply laws of
mechanics to analyze the vertical motion of the launched rocket.
DATA
Rocket model: ____________________
Rocket mass with recovery wadding, but without the engine: ____________________
The table below includes data that is common to all groups, plus your group’s angles for launch:
Air Resistance on rocket
when using A8-3 engine
Engine Masses
Engine Stage Mass (kg)
Rocket Type
Air Resist. (N)
Angle
Measurements
Angle a
Angle b
Initial
0.0161
Awesome
0.44
1.
4.
End Thrust
0.0131
Alpha
0.47
2.
5.
End Coast
0.0105
Wizard
0.54
3.
6.
Viking
0.56
DATA & ANALYSIS
MAXIMUM MEASURED ALTITUDE
1. Calculate the rocket’s measured altitude using the data collected during the launch and the
equation shown below. Be sure to show all data and average angle calculations.
h
A
a
b
h=
B
ABsin(a)sin(b)
sin(a + b)
ROCKET MASS
2. Calculate the rocket’s mass at each engine stage listed above: Average Thrust Stage m1, End
Thrust Stage m2, and Average Coast Stage m3.
THRUST STAGE
3. Calculate the impulse from each of the forces (lift from engine, gravity, air resistance) acting on
the rocket during the Thrust Stage.
4. Use the impulse-momentum theorem to calculate the rocket’s velocity at the end of the Thrust
Stage.
5. Use an appropriate kinematic equation to calculate the upward vertical displacement of the
rocket during the Thrust Stage.
COAST STAGE
6. Calculate the rocket’s kinetic energy at the beginning of the Coast Stage (this is the same as the
end of the Thrust Stage.)
7. Use the conservation of energy equation to calculate the rocket’s vertical displacement during
the Coast Stage. Set the zero level for potential energy at the height where the Coast Stage
begins.
MAXIMUM PREDICTED ALTITUDE
8. Add the Thrust Stage and the Coast Stage displacements to determine the maximum predicted
altitude of the rocket above the ground level where it was launched.
QUESTIONS & CALCULATIONS
1. Calculate the percent difference between the maximum actual altitude and the maximum
predicted altitude.
2. Give a detailed account for any discrepancy between the actual and predicted altitudes.
3. Use a kinematic equation to calculate the rocket’s acceleration during the thrust stage.
4. Use a kinematic equation to calculate the rocket’s acceleration during the coast stage.
5. Calculate what the maximum altitude would be without air resistance. Use separate paper to
show all your work for this problem.
6. Use your altitude from the previous question to calculate the speed of the rocket as it hit the
ground if there were no air resistance. Use separate paper to show all your work for this problem.
7. Honors only: Calculate the actual drag force for the rocket. Show that this answer is accurate by
recalculating the predicted altitude and comparing to the actual altitude. Use separate paper to
show all your work for this problem.