Calculating Rocket Launch Height - Nebraska 4-H

N e b r a s k a
4 - H
Y o u t h
D e v e l o p m e n t
It’s Just Rocket Science: Calculating Rocket Launch Height
Outcome Area:
__ Healthy Lifestyles __ Life Skills __ Career Development
Curriculum Area: Aerospace
Specific Project (s): Aerospace 2, Aerospace 3, or Aerospace 4
Description of Activity: This activity will help youth determine more precisely how high their rockets go
when they are launched.
Age Level: 8 - 18
Group Size: Any size
Time Involved: Preparation time: 10 min Activity time: 60 min.
Materials Needed:
Altimeter Construction:
Protractor or Paper Protractor from Packet (If using the paper protractor, youth will need
to glue the paper protractor to cardboard for added strength.)
Masking tape
Heavy Washer
Altitude Calculations:
Sample Rocket Launch Data
Rockets Away Manual
Calculators (Optional)
Youth will understand how science and technology relates to their 4-H projects.
Youth will develop positive attitudes about science and technology.
Anticipatory Set:
Leader will ask youth to discuss how to determine how high their rockets fly when they launch
them. They may suggest that they can tell how high they fly by knowing how high other items
are in the area. If they do you can ask them how they know how high those objects are. If not, let
them determine their best theory for determining the height of their rocket launches.
Leader should explain that we can use measurements to determine more scientifically how
high our rockets fly. One method for doing this is to use an altimeter to determine the angle for
the highest point of the rocket launch.
Leader should use the enclosed diagram of a rocket launch to explain how the altimeter can be
used to determine rocket height. Using the diagram, demonstrate how a protractor can be laid
on top of the diagram to determine the angle of the rocket launch. From the angle, show
students how to use the Table of Tangents found on page 23 of your Rockets Away manual to
determine the tangent of that angle. The tangent can be multiplied times the distance between
the rocket launch pad and the observation location to determine the exact height of the rocket
Building an Altimeter:
You may either choose to use actual protractors or a paper copy of a protractor. If you are
using a paper copy, you will need to cut out the protractor and glue it to cardboard for additional
durability. First tie a heavy washer to some string using a double knot. Once you have the
washer secured to one end of the string, cut the string a couple inches longer than the radius of
your protractor. Using the string that has been secured to the washer, tie the opposite end of the
string to the center of the flat edge of the protractor. If you are using the paper version, you can
simply tape the string to the protractor. Make sure that it’s exactly in the center. If the string has
been secured in the center of the protractor, you will be able to swing the washer around the
curved edge of the protractor and it will remain evenly spaced around the curve.
Next cut a straw to be the same length as the flat edge of your protractor. Secure the straw to
the flat edge of the protractor, making sure that it remains perfectly parallel with the flat edge.
Your altimeter is now complete.
How to Use Your Altimeter:
Altimeters should be held at a right angle to the ground, with the flat edge toward the top. If
you’re having problems envisioning this, tell youth to hold it in their left hand like a trumpet. The
rounded edge should be toward the ground. The string and washer apparatus should swing
freely along the curved edge of the altimeter. When you have launched your rocket, you will want
to hold the altimeter in your left hand and use the straw to align the flat edge of the altimeter with
the peak of the rocket height. The rocket goes fast, so you may have to practice first on a
stationary object, such as a telephone pole, tall building, or grain elevator. Holding it steady at
the peak, bring up your right hand and hold the string against the altimeter. Then you can level
the altimeter like a table top to make the final reading.
HINT: When you are first practicing using your altimeter, you may find it helpful to have two or
more youth measure the angle of the same object and compare notes. It also is helpful to have
students round their angle to the nearest 5°.
Calculating the height of your rocket launch:
It is always good to do a few practice runs with the calculations before you actually launch,
however, if you choose to you can also launch your rockets and then do the calculations on the
actual data.
Using the Sample Rocket Launch Data, and the Table of Tangents Chart on page 23 of your
Rockets Away manual, determine the tangent for each of the launch angles on the sample data.
Next have students multiple the tangent of the angle with the distance from the rocket to
determine the actual height for each sample rocket launch.
Sample Rocket Launch Data
Launch Angle
Sample #1
100 feet
Sample #2
200 feet
Sample #3
250 feet
Sample #4
250 feet
ANSWERS: Sample Rocket Launch Data
Launch Angle
Sample #1
100 feet
100 feet
Sample #2
200 feet
116 feet
Sample #3
250 feet
175 feet
Sample #4
250 feet
117.5 feet
Remind students that by applying scientific measurements to their rocket launches that they
can be more precise at estimating the actual height of each rocket launch.
Additional Learning Opportunities:
1. Have youth launch their rockets and use two or more altimeter measurements to more
precisely determine actual height of rocket launches.
2. Apply knowledge of altimeter use to new subjects, such as how high Chimney Rock is if
you are standing in Gering. (HINT: Gering is approximately 18 miles from Chimney Rock).
3. Assuming that a youth launches a rocket three times on the same day, what factors may
account for differences in the height achieved by each launch.
Horton, R. L., Newman, B., Dandareau, C. (2006). Rockets away! A fun approach to
exploring the science of rocketry. Ohio State University Extension.
Glenn Learning Technologies Project (2004). Altitude Tracking. Available online: