You can also tell that there is human error by comparing your measures to the algebraic calculations. In this lab I learned a lot about force. Equlibriant force is equal in magnitude to a resultant, but opposite in direction. In this lab this was demonstrated by us adding weight to one side to make them both balance. This was showed in the lab by both sides of the string balancing out.
Resultant force is a single force that has the same effect on an object.
This was showed in this lab by adding weights to one side to help balance the circle in the middle. As you can see in trial one and trial two human error was a big error. The calculated force was 290.9. The mechanical error was friction.