System of equations with acceleration and tension

[Bob Rudd]

Homework Statement

So there is a pulley with 1 mass hanging from it. The string is wrapped around and one end is taped to the pulley so that only one end of the string hangs from the pulley. There is a mass of 100 grams attached to that string. Create a system of equations to find linear acceleration of the descending mass and the tension in the string connecting the mass to the disk.

Homework Equations

F=ma

The Attempt at a Solution

The first equation would be T=mg-ma because the body is falling downward. How would i find the other equation with T and a to help me create a system of equations

 

[haruspex]

Do you have any information about the pulley?