### Notes:

The Orbital Motion Interactive is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Interactive can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.

### Teaching Ideas and Suggestions:

This Interactive is intended for use near the early stages of a learning cycle on satellite motion and gravitation. It provides a strong visual of the notion of a tangential velocity and of a gravitational force directed towards the foci of the ellipse. Learners will quickly observe that the satellite speed is slowest when it is further away from the central body and fastest when it is closest. This is often described as a corollary of Kepler's second law of planetary motion. Learners should also notice that this difference in speed between the slowest and the fastest speed is most extreme for more  elliptical orbits. The observation that the gravitational force is directed opposite the satellite's motion as it is moving away from the central body helps explain why the satellite speed becomes less and less as the satellite moves further away from the central body. And the observation that the gravitational force is directed in the same direction as the motion while moving towards the central body provides a reasonable explanation of why the satellite speed is increasing as the satellite approaches the central body.

Our Orbital Motion simulation is now available with a Concept Checker. Do the simulation. Then follow it up with the Concept Checker.

### Related Resources

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Orbital Motion Interactive. These include:
• Minds On Physics Internet Modules:
The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignments CG8 and CG10 of the Circular Motion and Gravitation module provide great complements to this Interactive. They are best used in the middle to later stages of the learning cycle. Visit the Minds On Physics Internet Modules.

• Curriculum/Practice: Several Concept Development worksheets at the Curriculum Corner will be very useful in assisting students in cultivating their understanding, most notably ...

Inverse Square Law of Universal Gravitation
Satellite Motion

Visit the Curriculum Corner.

Additional resources and ideas for incorporating Orbital Motion into an instructional unit on Satellite Motion can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.

### Credits

The Physics Classroom would like to extend a special thanks to Nerd Island Studios for the creation of this HTML5 Interactive. Visit their website (http://www.nerdislandstudios.com) to see more great stuff by Nerd Island Studios.