Home School Life Journal

Home School Life Journal ................................................................................................................painting by Katie Bergenholtz

Model Rockets, part 1: Clinomoters

For the first class in my Experimenting with Model Rockets course at our homeschool co-op, I posed the question of how we were going to measure how far the individual rockets go up in order to determine the  effects of our various modifications to the rockets. They began listing all the"...ometers" they knew,  so they were on the right track. They had just never heard of a clinometers before. 
Clinomoters measure the angular height of an object or, in this case a point in the sky to which our rockets will ascend. This angle forms the angular side of a triangle. If we also measure the distance between where the sighters with the clinometers are and where the rockets are launched,  then we have the measurements of two sides of a triangle. Since we already know that if you know the measurements of two sides of a right triangle, you can easily determine the third side, and therefore, in this case, the height the rockets travel. This is called triangulation.
Triangulation has many applications. Forest rangers use it to determine the location of forest fires. Astronomers use it to determine the location of objects in space.
Our first task, then, was to make usable clinometers.  We used the printout in the GEMS teacher's guide Height-O-Meters, (you can download a free copy here).
Because the clinometers won't naturally point precisely at zero, we must calibrate them to accurately place them at zero, just as you would calibrate your bathroom scale to zero before using it. To calibrate the clinometers,  you must first measure the distance between the ground and the eye level of the user. A piece of tape is the put on the wall at that level and the user stands back from this wall, in the middle of the room, and sights the piece of tape with the clinometer. If the clinometer reads a few degrees on the plus side of zero, students place a paper clip that amount of degrees on the minus sside of zero. Likewise, if the clinometers reads a few degrees on the minus side, the paperclip should be placed the same amount of degrees on the plus side. Continue to adjust the position of the paperclip until it read zero when sighting the tape. Students can work in pairs to complete this task so that they can help each other. Now the clinometer is calibrated to the user.
Next week we will use them to measure the height of a stationary object so that they can get used to using the clinometers in a circumstance when they can take all the time they need to learn the skill.


  1. How interesting - it sounds like a great topic for a science class!

  2. Wow!! I am SO impressed! :-)

  3. Why yes we will be studying rockets in a few months, and I will use this lesson then. I'll also have to reread this when I don't have a fever and am rather sleep deprived because I didn't completely follow the math.

  4. Thanks for hosting - it feels great to have science posts to link up!


Thank you so much for taking the time to comment. It means so much.