What Is the Acceleration and Tension in a Frictionless Inclined Plane System?

[anim8or]

Homework Statement

If m₁=m₂=1.0 kg and θ=30°, what will be the acceleration of the system? Calculate the tension in the cord, if a block m₁ lying on a frictionless inclined plane and is connected to a mass less cord. Assume m₁ is moving down the plane for A), and for B) m₁ is in the opposite direction. C) If m₁= 1 kg and θ=30°, and the system remains at rest, what must the mass of m₂ be? Calculate the tension.

Homework Equations

ƩF=ma

The Attempt at a Solution

For part A
I have this so far
m₁ x: ƩF=mg(sin30°)-T=ma
T=mg(sin 30°)/ma
y: ƩF=N-mg(cos 30°)=0
N=mg(cos 30°)
m₂ y: T-mg=ma
T=ma+mg
T₁=T₂
therefore, ma+mg=(g(sin 30°))/a
so to solve for a I end up getting
a²+ ga - gsin30°=0
so do I just do the quadratic formula here or am I going the wrong way about it?

Here's the problem if you need to see the picture

http://imageshack.us/f/812/ue4y.jpg/

 

[Maiq]

No need for the quadratic formula. look at your Forces in the direction. You made a mistake.