Hovercraft Addition – Collisions!

Jim DHS Oct '12by:  Jim Fiddes I recently used this extension of the balloon-CD hovercraft plans in Norm Barstow’s blog for a middle school physical science lab, but it could be easily adapted for a high school IPS class. It works as inquiry for higher-achieving students, but just as well with more detailed direction, for regular classes. HC1By the time you do this collision addition, your students should be attuned to the fact that “hover” means just that—there is no lateral motion without some sort of propelling force. The hovercraft will just sort of sit there and maybe spin a little. Students looking for more dynamic action will be disappointed. As a mid-point review between the two hovercraft labs, you may show the “Junkyard Wars” episode on hovercraft, in which it’s abundantly clear that hovercraft need two forces—one to levitate the craft, and another to propel it. Students provide the propelling force, accelerating one levitating hovercraft into another, and observing the results. Illustrationwww.xinventions.com Basically, this addition explores the ideas of Newton’s Three Laws, inertia, momentum (First Law), Newton’s Second Law (force equals mass times acceleration), and even Newton’s Third Law (action-reaction) using collisions between differently-weighted hovercraft. Weighting is done with the simple addition of pennies or washers onto the CD (see below). While it’s difficult to quantify acceleration here, mass can be calculated and compared. If you have a SmartBoard, you can do some cool on-screen demos as lab prep and summary, too! More about this later! Read the rest of this entry »