Here's a post from a usenet group regarding a demo for a fifth grade school presentation on relative planetary surface gravity. It looked pretty effective, so I thought I would pass it on: ================== From: Brian Tung Date: Sun, Mar 5 2006 2:01 am Groups: sci.astro.amateur <snip> I started out with a little planetary gravity demonstration: I divided the class into 10 groups of three, and gave them each secret instructions to fill a pencil cup with a certain number of marbles and a certain number of cotton balls. Each team got, in effect, a planet, and the weight of the pencil cup was according to the surface gravity of the planet (pretending that there is a surface at the cloudtops of the gas giants). So, for instance, the cup for Jupiter weighed about two-and-two-thirds as much as the cup for Earth. I designed this demonstration because they often teach you to figure out what you would weigh on each planet, but you don't get a visceral feel for it. After filling the cups, each team went around and tried to guess which other cups were which planets. Pretty much, they all got Jupiter and Pluto right, but they were surprised by some of the other ones. In case you were interested, here are the relative weights I used: Jupiter 2.64 Saturn/Neptune 1.13 Earth 1.00 Venus 0.90 Uranus 0.89 Mercury/Mars 0.38 Moon 0.16 Pluto 0.06 I also brought a cup that I prepared (because it contained lead shot, and please, no Cheney jokes) for the Sun, which has a surface gravity about 28 times that of the Earth. They were suitably impressed by how heavy that thing was. <snip> ====================== __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com