Measuring Mass of a Hanging Weight: Stephen's Question

[StephenDoty]

We did a lab where we had to measure the mass of a weight that was hanging from an air track which pulled the glider through two timegates positioned above the air track.

I have to find the force of the hanging weight. F=mg my first mass was .27004kg and the gravity is obviouly 9.8m/s/s.

So do I use F=.27004kg * (9.8m/s/s)
or
F= .27004kg * (-9.8m/s/s)

Do I put the negative sign with the gravity as the force is downward with the hanging weight?

Thank you
Stephen

 

[rock.freak667]

The - sign only indicates a direction. So you can leave it as +ve once you remember that putting g as +ve says that the downward direction is taken as +ve.