I am currently working on my physics lab report, and my question is "What effect does the mass have on the change of acceleration?" The lab currently consist of two pulleys hanging on each end balancing weighing 100kg, i continuously add 10kg for each turn, i then record the time of the larger mass it takes to reach the table. I am using a digital timer to time each time the weight reaches the table. I am having trouble understanding how to find the uncertainty for my data, as i have barely understanding from it. Here's a picture of my data. And sorry for my lack of grammar as I do try my best. Thanks and much appreciated if anyone could help me!