Let's say a ball falls from a height of 20m from the ground. g=9,8m/s^2. m=3kg. Consider resistance of air in a qualitative way. What's the formula for the work done by gravity? So, I just thought about this question. I wonder if W=F*s should be applied. Does gravity still do 588J of work? Or should we take into account that F is smaller because of air friction? All this concept of work is very new to me and I googled for similar questions but couldn't find any web page alluding to my problem.