This is not a homework question. I though I post this here because more members here a helping us, rather than the general physics question. Please don't move this: This post might be long to read, but is easy. I thank you if you take the time to read it. So I am confused on why this is. I was done with my lab and got the result. Now I am writing a lab report. I have the following data : With constant hanger mass of 0.125kg, the accelerations are : Trial # ---- acceleration of experiment ---- acceleration of frictionless 1 ------ 2.5200 ------ 4.77 2 ------ 1.4440 ------ 3.99 3 ------ 0.7200 ------ 3.40 4 ------ 0.1460 ------ 3.01 5 ------ 0.0536 ------ 2.68 This is a pulley system. The hanger is the one hanging at the end of the table. A puck is connected with a "massless" string which runs through a "massless" pulley, which connects to a hanger. So in this trials the hanger's mass is constant and the pucks mass is increases with trial. Although it is not shown. I hope you understand what I said thus far. So from the data you can see that the force of friction is decreasing as the mass increases. Just by subtracting the acceleration of experiment by the below trial shows that the difference in the acceleration is decreasing, thus the force of friction is also decreasing. The acceleration of frictionless is the theoretical acceleration. Why is it the in a as a object weight increases, it experiences less force of friction?