Understanding Newton's First Law for Force Tables

[azn4lyf89]

I did an experiment on a force table with pulleys and weights. We were suppose to, through trial and error, find weights and add them on strings that were placed at different angles, so that the ring in the middle would become centered. Attached is the data table. I am suppose to calculate the algebraic sums of the x and y-components and see if Newton's First Law is verified within experimental error. I know that the sums should add up to zero, but am I suppose to put a negative value on the component that is opposite from the other? Should the X components add up to be zero and the Y components or together should they equal zero?

 

[tiny-tim]

I am suppose to calculate the algebraic sums of the x and y-components and see if Newton's First Law is verified within experimental error.
I know that the sums should add up to zero, but am I suppose to put a negative value on the component that is opposite from the other?
Should the X components add up to be zero and the Y components or together should they equal zero?

Hi azn4lyf89!

i] Yes … components in the negative direction are negative.

ii] This is vector addition … the vector sum must be zero, so the X components and the Y components must equal zero separately.