Calculating Tension in a Frictionless Slope Problem

[juliadufosse]

Homework Statement

A 5.4 kg box is on a frictionless 44^\circ slope and is connected via a massless string over a massless, frictionless pulley to a hanging 1.4 kg weight.
What is the tension in the string once the box begins to move?

Homework Equations

Fnet=ma

The Attempt at a Solution

I attempted to answer this using: w1= weight force of 5.4kg
w2+ weight force of 1.4kg and T= tension exerted on string by each of the masses, mass 1=5.4kg and mass2=1.4kg

So I have:
T-w1*sin(44) = m1a1
T-w2=m2a2
a1=(m1/m2) a2

but this gives me the wrong answer what am i doing wrong?

 

[rl.bhat]

Hi juliadufosse, welcome to PF.
In your attempt the first equation is correct.
In the second equation, since mass is going down, it should be
w2 - T = m2a2.

 

[juliadufosse]

if mass is going down shouldn't weight be negative and T-w2=m2a2

 

[rl.bhat]

if mass is going down shouldn't weight be negative and T-w2=m2a2

Then a2 should also be negative, because both of them are in the same direction.