1. I learned that when you pull one thing on or thought another It causes friction to act on the objects to make it harder to push or pull. When the weight is greater it increases friction and if the surface is smaller whith the same weight it increases it too, and if you change the surface that it is on then it changes how much friction affects it.
2. We measured sliding friction by using a spring scales in class. Friction can be measured when it is pulled back on the object. So when you pull,you can measure the resistance with a spring scale.That is how we measured sliding friction.
3.I learned that the variables that were the same in one experiment were weight,length,time,slope,surface, the variable that were not the same was surface area.