International Baccalaureate Physics
4/PSOW
Greetings exalted leaders of Sri Lanka during 1915,
I am excited to offer my services as a rocket scientist to help our country lead the world in
rocketry. It is certainly very progressive of you to focus your resources on scientific research.
I would like to propose an experiment that investigates how the horizontal distance travelled
by a rocket is affected by the angle of launch. Details are provided below.
Scientifically yours,
Nicholai Go, Sri Lanka class of ‘09
Rocket Design Lab
Problem: How will changing the angle of launch affect the horizontal distance traveled by
a rocket?
Hypothesis: I think that as the angle increases from zero to 90 degrees, a graph of horizontal
distance vs. angle will look as pictured below.
Distance
Launch Angle
Independent Variable: Angle that the rocket is launched at (measured relative to the
ground).
Dependent Variable: Horizontal distance traveled by the rocket.
Controlled Variables: (these will remain the same)
 Rocket used
 Pressure used to launch rocket
 How deep the rocket is placed on the launcher
 Weather (to be kept as constant as possible by performing all trials within a short time
frame)
 Height that the rocket is initially launched from.
Materials:
 Pneumatic rocket launcher made of PVC pipe
 Foot powered air-pump
 Paper rocket
 Protractor
 Measuring tape
International Baccalaureate Physics
4/PSOW
Diagram:
Rocket
Launch
Angle
Valve

PVC pipe
Foot
Pump
Pressure Gauge
Method:
Using the diagram above:
1. On the main body of the rocket, make a small pencil mark indicating 10 cms (from the
bottom of the rocket).
2. Place the rocket on the launcher so that the 10cm mark rests exactly on the tip of the
launcher (in other words, the rocket is placed so that exactly 10cm of it rest on the
launching tube).
3. Set the launch angle of 30 degrees (measured relative to the ground) for the rocket
using a protractor.
4. To launch the rocket, pump the foot-pump 20 times (and, for successive trials, simply
increase the pressure to an equivalent amount).
5. Open the valve, allowing the rocket to launch.
6. Record the horizontal distance traveled by the rocket.
7. Repeat steps 2-6 for all necessary launch angles and trials.
 In order to perform an adequate number of trials, launch the rocket at an angle
increasing in increments of 5 degrees until the launch angle reaches 70
degrees.
 For each launch angle, perform two trials and record the distance traveled on
both trials.
8. In all trials, measure the amount that the rocket is blown off a ‘straight’ path by any wind.
If this displacement is more than 10% of the total horizontal distance traveled, repeat the trial
and discard any results obtained from the wind-affected trial.
International Baccalaureate Physics
4/PSOW
Here is an example table that could be used to collect data from the experiment.
Angle of launch /
degrees
(above the
horizontal)
5
10
15
20
25
30
35
40
45
50
55
60
65
70
Trial 1
Horizontal
Distance / m
Trial 2
Average Distance
/m
Trial 3