Acceleration of 4kg Object w/ Force at 37 Degrees

[zafer]

Homework Statement

Find the acceleration of the object in the figure with mass 4 kg when it's applied a force of a)50N b)100N and which makes an angle of 37degrees.(sin 37=0.6,cos 37=0.8)
[PLAIN]http://img97.imageshack.us/img97/5863/forceg.png

Homework Equations

F=ma

The Attempt at a Solution

I have tried to take first Fx=ma for 50N which goes in the direction of x-axis I got 10m/s^2 which is correct but when i try with 100N with Fy=ma I don't get the correct answer.Or with Fx=ma
could you please help me?

 

[Fightfish]

When the 100N force is applied, note that there is a net upwards force on the block and hence the block has an upward acceleration. Factor that in and you should get the correct answer.

 

[zafer]

When it applied 100N it should be 20.6m/s^2 upwards direction.