This section is a lot more theory than construction, which is good because if there was no theory in this basement we couldn’t call this science.

For our force measurement we are going to use springs as discussed earlier. I explained in “Lift and Drag Measurement Gauge” a little about linear springs. But here is a little refresher. Your common daily use springs are pretty closely defined as linear springs. This means that the force exerted by the spring varies linearly with the length stretched by the springs. This idea is captured by the equation F=-k*x. Force equals the negative of the spring coefficient, k, times the length stretched, x. There is a negative because if you pull it to the right, it pushes to the left. Not all springs are linear and even your common springs are not exactly linear, but it is close enough. As you dig into science, you will find that many of the things you learn are not exact but pretty close. Maybe that is more true for engineering than science.