Bottle Blast-Off!
Rocket Height Calculator

Now you're ready to figure out how high your rocket flew.
What Do I Do?
Step 1
Collect measurements for your rocket’s flight from three different people. Each person probably got a slightly different measurement.

Step 2
To improve the accuracy of measurement, sometimes scientists take many measurements and then average the results. To get an average, add up the three measurements for your rocket and divide by 3.

     Measurement 1: ________ degrees
     Measurement 2: ________ degrees
     Measurement 3: ________ degrees
                      Total: ________ degrees/3 = ____average angle in degrees

Step 3
Take a look at the Rocket Height Calculator Grid.
Each division on the grid represents 100 cm in the real world. Imagine that your eye is right by the protractor in the lower left-hand corner of the grid. The line at the bottom of the grid is a line parallel to the ground, right at the level of your eyes.

Step 4
On the protractor in the corner of the grid, find the average angle that you calculated in Step 2. Mark this angle on the protractor.

Step 5
Place your ruler so you can draw a line through the mark on the protractor and through the corner of the grid. Extend this line all the way across the paper.

Step 6
The people measuring how high the rocket flew stood 10 meters (1,000 cm) away from where the rocket was launched. That’s why the rocket launch site marked on the grid is ten squares away from the protractor. Starting at the rocket launch site, draw a straight line that’s perpendicular to the eye-level line. Draw this line all the way up to the top of the grid.

Step 7
Now you have a triangle. At one corner of the triangle is your eye; at another corner is the rocket launch site; at the third corner is the rocket in flight.
      The height of the triangle tells you how high your rocket flew above eye level.

     The height above eye level is _____ cm.

Step 8
The eye level of the average American twelve-year-old is about 140 cm. So add 140 cm to the number you got in Step 7 to get the height of the rocket’s flight.

     The height of the rocket’s flight is ______ cm.


For tips on how to use this trick with a class or group, go to the Teacher/Leader
Math Explorer Home


© Exploratorium