i'm sure for you veterans of the physical sciences you'll have no troubles with my answer .. i digress. i don't fully understand the concept that gravity (on earth as it may be) is independent fully of mass. would not the mass of the object (say a hammer VS. a house), if gravity is the force of attraction between some two objects (the earth and the hammer/house), have an effect? should not the house and hammer be pulled to the earth at different accelerations? if not (so says my physics text), is it because both their masses are just negligible as compared to the earth's? i hope i posed my question in a clear manner. if not, i'll eagerly rephrase. thanks guys.