What is q and what is the charge (negative or positive)?

[SkyHawkProfessor]

Three identical point charges, each of mass m 0.10kg and charge q, hang from three

strings, as pictured below. The lengths of the left and right strings are L 30.0cm

and the angle is 45.0^o.

Just on looking at the picture I think the charge is positive since there is tension separation the three masses. I'm confused on how to get q. Should I be looking at the space separating the masses on the x-axis? or be more focused on gravity's role?

 

[haruspex]

View attachment 94523
Three identical point charges, each of mass m 0.10kg and charge q, hang from three

strings, as pictured below. The lengths of the left and right strings are L 30.0cm

and the angle is 45.0^o.

Just on looking at the picture I think the charge is positive since there is tension separation the three masses. I'm confused on how to get q. Should I be looking at the space separating the masses on the x-axis? or be more focused on gravity's role?

Draw a free body diagram for one of the side masses and consider the forces acting on it.
It doesn't matter whether q is positive or negative. What matters is that the three charges are the same, including their signs.