why is W=m*g relevant if I am standing still and not moving ?

1. The problem statement, all variables and given/known data



Why is gravity still 9.81m/s/s when we are standing still ? and why do I have a weight when I am standing still ?



2. Relevant equations

F=m*a

W=m * g



a= (final velocity - initial velocity)/ time





3. The attempt at a solution



So it requires more of a theory explanation and I'm a touch confused...



If acceleration is based on a final velocity minus the initial velocity and then divided by time, how can I be accelerating at 9.81 m/s/s if I'm standing still ?



If I jump in the air the earth pulls me back towards its center at 9.81 m/s/s. That much makes sense. ..but standing still on the footpath I don't quite get how I can be accelerating towards the center of the earth given I am having no change in velocity, and a change in velocity is demonstrated through acceleration.



Obviously I'm missing something fundamental here

1. The problem statement, all variables and given/known data







2. Relevant equations







3. The attempt at a solution

via Physics Forums RSS Feed http://www.physicsforums.com/showthread.php?t=703881&goto=newpost