To find the point between two massive spherical bodies at which their gravitational fields cancel is an apparently simple problem usually found in introductory physics textbooks. However, by noting that such a point does not exist when the distance between the spheres is small and one of the masses is much smaller than the other--e.g., between the…

Presents a class activity in which students use trigonometry to calculate the height attained by a water rocket. Provides a lesson plan that includes a list of materials needed, procedures to carry out the experiment, suggestions to extend the activity, and a reproducible worksheet for the students to register their calculations. (MDH)