Experimenting with Model Rockets, part 2: Using Clinometers

Last week we made and calibrated our clinometers in order to have instruments that will measure the heights the rockets we will construct will attain. This week we practiced using the clinometers to determine the height of the basketball net's pole. First we measured the distance between the base of the basketball net's pole and where we would be sighting our clinometers from 8 meters away. We used a piece of string 8 meters long and stretched it out from the base of the basketball net's pole and chalked a mark, making a semi-circle.

The students then stood with their toes on the line and sighting their clinometers to the top most point of the basketball net's pole. They then noted this number, using the term degrees after their number, in their notebooks. Any student whose number differs from the others by 10 degrees or more should be helped either by another student or by the teacher.

Once inside you can remind them that the clinometers measure the angular height of an object in degrees, but that they can couple this measurement with the baseline measurement they made (from the base of the pole to where they stood, or in this case, 8 meters) to determine the figure out the linear height of the pole above ground.

To do this, we made a graph using the Height Finder chart in the GEMS Height-O-Meters Teacher's guide. As we are taking our measurements from eye level and not ground level, to accurately determine the measurement, you must add the eye-level measurements for each clinometer user taken during the first class. 

Now that they understand how to do triangulation, during the next class we will be designing our rockets.