This unique five-minute video features a NASA astronaut demonstrating centripetal force in ways students cannot observe in daily life. The video was shot in a weightless environment -- on board the International Space Station. The astronaut swings a tethered tool around a cord, rotates a bag of tea to show how air bubbles are pushed to the center, and spins a water droplet to show deformation resulting from centripetal force. The video was designed to promote understanding of the force that keeps planets in their orbits and keeps humans in their seats on a looping roller coaster. The video itself was developed by the NASA Teaching from Space program, and packaged to include background information and discussion questions.

PBS Learning Media is a growing collection of videos, lessons, and activities assembled by researchers, scientists, and experienced teachers to promote the use of digital resources in the classroom.

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