Leaderboard

Hello, hopefully I am posting in the right area. I apologize if not. I am studying the physics iBook "Physics - fundamentals and problem solving" , which is an absolutely amazing book by the way.. i had no idea one could teach through a book with a few videos and get the same results as a full on physics classroom. But anyway, there is a concept I am having trouble grasping. I understand that the force of the gravitational pull is mass times acceleration of gravity but what I'm having trouble with is what we are measuring when we stand on a scale. I was browsing the net and I got onto the Wikipedia site, http://en.wikipedia.org/wiki/Pound_(mass) , where it says that pounds are units of mass in the imperial system we use here in the US. It also goes on to talk about pound-force and pound-mass and that is where It gets me confused. When I step on a scale, is that scale measuring my mass? or my weight here on earth? Pound force would be weight (mass times gravity) and pound mass would just be mass I suspect?it might be a silly question to most, but I've never heard of this. and coincidentally, if one pound is .45359 kilograms, does that mean 1 pound-mass or pound-force equals .45359 kg? When they step on a scale with kilograms, is it measuring their weight or mass? In weight lifting, or on truck scales in kilograms, is that the mass or the weight? Thanks!