DL-Circular Motion and Gravity

Demo - Twirling tape.  Twirl a roll of masking tape around your head.  Have the students predict where the tape will go when you let go of it at a particular point.

Demo - A cup of water on a plate suspended by strings.  I twirl it above my head, and we go beyond  the notion of a fictitious "Centrifugal Force" that keeps the water in the cup

Lab - Plate Lab.  Students make predictions with a plate and a marble.  One of the plates has a quarter of it missing.

Demo - Orbit Sim and Sheet of Rubber.  I talk about the Newtonian mechanics of orbit and demonstrate an elliptical orbit.  I explain it using conservation of angular momentum, and then also energy - why it is fast when it is close and why it is slow when far.

To demonstrate general relativity,  I get the kids (I don't have a fancy setup like the dude in the video) to stretch a large piece of lycra fabric about 12" above a desk.  (Sheet of rubber!!!)  First I place a couple billiard balls (mechanics cupboard) on to show how warping space time causes attraction, then I put a 2 kg mass in the center (it will rest on the table) and show how a small steel marble can orbit.  Then we go back to the orbit sim and try to picture the sheet of rubber.  The sheet of rubber is in a box in the center glass cabinet.  The large masses are in a cupboard on the west wall south of the sink on the bottom shelf.

Lab - Orbit Lab - they use DOS box to run an old simulation that I wrote years ago.  The website pretty much lays it all out:  Orbit Lab 

Demo - Vertical Circle with a Cup of Water!!

Demo - I Demonstrate a centrifuge.  I put a test tube full of muddy water in it, and it settles out clear pronto.  I also discuss other centrifuges in the house - a lettuce centrifuge, and a wet clothes centrifuge. ; - )

Demo - stuff

Lab - stuff