Need help calculating friction and normal force for "Measuring Friction" Lab Hey guys, I'm not great at physics and have a lot of work ahead of me so I could use some help. The lab setup is a wooden block sliding on a wooden surface. There is a weight attached to the block by a string that's hanging from a pulley at the end of the wooden surface. This guy right here ----> http://imageshack.us/photo/my-images/820/40999170.jpg/ if I'm being unclear. I have found the weight it takes to start the object moving (static friction) and the weight it takes to move the block at a constant velocity (kinetic friction). I did this a bunch of different times with different weights and surface areas and now I get to do a bunch of calculations. SO, I could really use a walk-through on simply how to calculate the friction and the normal force, because I have to do it 12 different times. For example, my first calculation was for the wood on wood block (weighing 128.1g) with a 100g weight on top, it took 81.1 grams to start it moving (static friction). If someone could just give me basic steps to work this out, it would help a lot. (Find friction force and normal force). This is probably simple but I don't have a physics brain and I'm new to the course. So thanks for the help.