September 1, 2007 Issue

Physics To Go 32 - Rocket/Hero's engine

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Physics in Your World

Newton’s Laws of Motion image
Photo credit: The Video Encyclopedia of Physics Demonstrations

Newton’s Laws of Motion

This photo shows a version of Hero's Engine, in this case a flask of water with two openings, pivoted so it can rotate. Click on the photo to see what happens after the Bunsen burner has brought the water to a boil. Two jets of steam shoot out, and the flask spins, in a demonstration of action and reaction (see Rocket Principles and Newton's laws). The reaction forces produce a torque that spins the flask.

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Physics at Home

Soda Pop Can Hero Engine

You can demonstrate action-reaction with an easy-to-build Hero's Engine built from a soda can. Just follow the directions at Soda Pop Can Hero Engine, and be sure to have an adult working with you.


From Physics Research

Rockets and Robert Goddard image
Image credit: NASA/Goddard Space Flight Center; image source

Rockets and Robert Goddard

Robert Goddard is shown here (hi-res image) in 1926 with the world's first liquid-fueled rocket, which reached an altitude of 41 feet.  For more information, see the NASA page Robert Goddard: a Man and His Rocket. (You'll find out how his work--and his understanding of Newtonian mechanics--was trashed in a 1920 New York Times editorial, which the Times retracted just after the launch of Apollo 11.)

(This feature was updated on July 16, 2013.)

Worth a Look

The Beginner's Guide to Propulsion

See The Beginner's Guide to Propulsion, from the NASA Glenn Research Center, for a description of how Newton's laws explain rocket propulsion.

This feature was updated on July 16, 2013.

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