Physics Lab: Calculating Tension with T=m(g-a)

[hailbo]

I'm doing a physics lab right now and to find tension we use the equation T=m(g-a) where m is the suspended mass and t is tension. I'm not sure if g should be negative or positive. I'm guessing negative but I am not to sure.

 

[CWatters]

The sign of "g" will depend on which direction you define "a" to be positive.