i have a PHYSICS exhibition?? any topics to work on..??

How about establishing your own value of the gravitational constant g. Heyl P.,Chrzanowski (1942) was only successful of establishing the value up to the third decimal place 6.673 x10-11 m3Kg-1s-2. He used three different materials: gold, glass, and platinum. In his experiment he found out that the value of g is not constant as it should be. For gold it is 6.6781666666x10-11 m3Kg-1s-2, for glass it is 6.674x10-11m3Kg-1s-2, and for platinum it is 6.664x10-11 m3Kg-1s-2. Please check this link for the proper exponents of the unit http://www.blazelabs.com/f-u-massvariation.asp Good luck...