Solving a Physics Problem: Accelerating Plane

[huskydc]

this is another post, but i just want to post it in this room and see if ANYONE knows how to solve this:
I've tried everything, now I'm getting depererate

An inclined plane that makes an angle of 28° to the horizontal is mounted on wheels. A small block of mass m = 1.2 kg rests on the plane, held there by a coefficient of static friction µ = 0.73.


The plane is accelerating to the right. What is the minimum acceleration in order that the block slides down the plane?

Any help would be great !

 

[Pyrrhus]

Apply Newton's 2nd Law and solve for a.

The 0 degrees with the horizontal system of coordinates will be the easier one.

 

[huskydc]

i tried literally everything, would anyone please help me solve it? lol...

i came up with the following, after lots of equation, i used it to solve for a, didn't work either

g sin (theta) - mu (a sin (theta) + g cos (theta) ) = a cos (theta)

 

[Pyrrhus]

Well, with the coordinate system set as i said above.

$$\sum F_{x} = ma = - n \sin \theta + F_{f} \cos \theta$$

$$\sum F_{y} = 0 = F_{friction} \sin \theta + n \cos \theta - mg$$