# Watch an Astronaut Test Newton's Second Law of Motion in Space

In a new video, NASA astronaut Randy Bresnik presents the latest installment of NASA's educational series "STEMonstrations" and highlights Isaac Newton's second law of motion by sending three objects into free flight inside the International Space Station.

"Now, on the space station, we live in a microgravity environment," Bresnik says warmly at the beginning of the video. "Do you think the laws of physics will hold up? Come on! Let's go find out."

"STEMonstrations" is hosted by astronauts living aboard the space station. NASA invites educators to share these microgravity experiment videos with their sixth-, seventh- and eighth-grade students, according to a statement by the space agency. [Teacher-Astronauts Helm NASA's Year in Education Aboard the Space Station]

Newton, best known for an inspirational gravitational encounter with an apple, likely a myth, developed three laws of motion and first published them in his "Mathematical Principles of Natural Philosophy" (known more commonly as "Principia") in 1687.

Written as F = ma, Newton's second law of motion states that the force acting on an object (F) is equal to the object's mass (m) times the acceleration it undergoes (a). So, in the case of a rocket, the heavier the spacecraft is, the more force it needs from engine thrust to start accelerating.

In the video, Bresnik uses a bendy slingshot to put a ChapStick, a miniature replica of a space capsule and a large stuffed storage bag all into motion. Sure enough, the ChapStick goes flying faster than the big bag, because if the force acting on the object remains constant in all the examples, the larger object will not be able to accelerate as much.

The NASA Office of Education hosts the "STEMonstrations" videos with additional space-related multimedia content for educators and students. NASA's Education Calendar also provides teachers with ways to plan their classroom activities around future educational content.

"STEMonstrations: Newton's 2nd Law of Motion" was released on Feb. 28, but the video was filmed several months ago; Bresnik has been back on Earth since Dec. 14, when he ended his 139-day space station mission.