ISEN-ASTC-L is a service of the Association of Science-Technology Centers Incorporated, a worldwide network of science museums and related institutions. ***************************************************************************** Hi, all - If your institution (or an institution you know or have visited) has either of the following types of exhibits, would you please email me off-list ([log in to unmask]) to let me know? 1) A "giant pulley" exhibit - the kind where visitors sit on a series of chairs (usually 2 or 3), each of which has a pulley system of a different mechanical advantage (i.e., different numbers of pulleys/ropes), and try to pull themselves toward the ceiling using the pulley systems. 2) A "giant lever" exhibit - a) The first-class lever kind, in which a heavy load is placed on one end of the lever, and ropes of varying distance from the fulcrum are placed on the other OR b) The second(?)-class lever kind, in which the fulcrum is on the floor and 2 ropes are attached on a lever extending toward the ceiling at different distances from the fulcrum. (When I've seen visitors use this exhibit, it's often been as a "tug-of-war".) Thanks, Bill Bill Watson Research Assistant, SCALE-uP Doctoral Candidate, Curriculum & Instruction The George Washington University (202) 994-1171 www.gwu.edu/~scale-up *********************************************************************** For information about the Association of Science-Technology Centers and the Informal Science Education Network please visit www.astc.org. Check out the latest case studies and reviews on ExhibitFiles at www.exhibitfiles.org. The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To learn more, visit http://www.lsoft.com/LISTSERV-powered.html. To remove your e-mail address from the ISEN-ASTC-L list, send the message SIGNOFF ISEN-ASTC-L in the BODY of a message to [log in to unmask]