Film: "Zero G", sound, 14 min.

Film: ZERO-G, (HQ 260-A), a NASA film, from Ames Research Center. Film Title: Zero G 1975 Level: Upper elementary-Adult. Color and Sound. Description: The film shows numerous demonstrations of weightlessness and crew activities in Skylab. The universality of gravitation is illustrated by scenes from the Moon including the simultaneous dropping of feather and hammer on Apollo 15. The question "Why do we feel weightless in Skylab ?" is asked. The satellite is only 435 kilometers from earth and is not beyond the earth's gravitational field. A review of the basic principles of orbit is given, in order to explain that Skylab is accelerated equally by gravity so that it has no relative acceleration. The sensation of weight depends on the presence of support forces. In orbit there are none; a satellite is in steady free fall. The film states Newton's three laws of motion. Striking illustrations of these laws in the zero-g environment of Skylab are shown. The film conveys an understanding of the phenomenon of weightlessness or zero-g in a freely falling spacecraft. The film shows and discusses some remarkable phenomena in zero-g to promote student understanding of Newton's laws of motion and gravitation. The film is suitable for general audiences and for classroom use from junior high school to beginning undergraduate levels. Length(min.): 14