A box over an inclined plane with a mass, no friction

[SqueeSpleen]

Homework Statement

We have an inclined plane with a mass $M$ and an angle $\alpha$ and a box of mass $m$ over it.
Everything is at the instant 0 (it's a problem of static, no dynamics).
a) What's the acceleration in the component x of the box?
b) What's the acceleration in the component y of the plane?
c) What's the acceleration in the component x of the box?

Homework Equations

Newton laws, momentum conservation I guess.

The Attempt at a Solution

I have tried but I'm failing.
The solutions are supposed to be
a)
$$
a_{1x}
\dfrac{ -m_{2} \cdot g \cdot \tan (\alpha) }{ m_{2} \sec^{2} (\alpha) + m_{1} \tan^{2} (\alpha) }
$$
b)
$$
a_{2x}
\dfrac{ m_{1} \cdot g \cdot \tan (\alpha) }{ m_{2} \sec^{2} (\alpha) + m_{1} \tan^{2} (\alpha) }
$$
c)
$$
a_{2x}
\dfrac{ -( m_{1} +m_{2} ) \cdot g \cdot \tan^{2} (\alpha) }{ m_{2} \sec^{2} (\alpha) + m_{1} \tan^{2} (\alpha) }
$$
I've tried several times, and the best I have got for a) was
$$
a_{1x}
\dfrac{ -m_{2} \cdot g \cdot \tan (\alpha) }{ m_{2} \sec^{2} (\alpha) + m_{1} \sec^{2} (\alpha) }
$$
I'm surely missing something.
The reasoning beggings as follows:
The magnitude of the force of the box over the inclined plane is $g m_{1} \sin (\alpha )$ as is the normal component of the gravity. That force as a direction $(\sin( \alpha ), - \cos(\alpha))$.
Here is where I got confused. I know if the ramp has infinite mass, or is "glued" to the floor which to this porpuse is the same, the box would only have left a the tangent component of the force.
The thing is, I'm not sure how acceleration gets distributed between two masses.
I remember that in the case of colliding "balls" it was something like
$$
\dfrac{ m_{1} }{ m_{1}+m_{2}}
$$
and when assuming that is when I almost got the result, but I had $\sec$ in both places, no $\tan$. So I guess I'm missing a $\sin$. Any one knows where can I read theory to help me understand this a bit better and solve this problem? I guess if I can start playing with Newton Laws until I get the correct result, but I would like to have a better understanding.

 

[vela]

Homework Statement

We have an inclined plane with a mass $M$ and an angle $\alpha$ and a box of mass $m$ over it.
Everything is at the instant 0 (it's a problem of static, no dynamics).

If this is a statics problem, then the answer to all of the questions below is 0.

a) What's the acceleration in the component x of the box?
b) What's the acceleration in the component y of the plane?
c) What's the acceleration in the component x of the box?

One of these is supposed to be the x-component of acceleration of the plane, right?

Homework Equations

Newton laws, momentum conservation I guess.

The Attempt at a Solution

I have tried but I'm failing.
I've tried several times, and the best I have got for a) was
$$
a_{1x}
\dfrac{ -m_{2} \cdot g \cdot \tan (\alpha) }{ m_{2} \sec^{2} (\alpha) + m_{1} \sec^{2} (\alpha) }
$$
I'm surely missing something.
The reasoning beggings as follows:
The magnitude of the force of the box over the inclined plane is $g m_{1} \sin (\alpha )$ as is the normal component of the gravity. That force as a direction $(\sin( \alpha ), - \cos(\alpha))$.
Here is where I got confused. I know if the ramp has infinite mass, or is "glued" to the floor which to this porpuse is the same, the box would only have left a the tangent component of the force.
The thing is, I'm not sure how acceleration gets distributed between two masses.
I remember that in the case of colliding "balls" it was something like
$$
\dfrac{ m_{1} }{ m_{1}+m_{2}}
$$
and when assuming that is when I almost got the result, but I had $\sec$ in both places, no $\tan$. So I guess I'm missing a $\sin$. Any one knows where can I read theory to help me understand this a bit better and solve this problem? I guess if I can start playing with Newton Laws until I get the correct result, but I would like to have a better understanding.

From your description, I have no idea what you were doing. Please show your work.

You mentioned conservation of momentum in the relevant equations. Did you use it?