Sliding mass on sliding incline

[zheng89120]

Homework Statement

A block of mass m slides down the incline of a triangular block of mass M. The angle of inclination is $$\theta$$. The trianguilar block is free to slide on a horizontal plane. Assume that all surfaces are frictionless. What is the acceleration of the mass M?

Homework Equations

F(net)=ma=0

The Attempt at a Solution

so basically i want to ask if my answer is correct, as I'm not familiar with this type of problem, i got:

F(horizontal) = mg cos $$\theta$$ sin $$\theta$$
a(M, horizontal) = F(horizontal) / (m + M)

is this right?

 

[PhanthomJay]

Homework Statement

A block of mass m slides down the incline of a triangular block of mass M. The angle of inclination is $$\theta$$. The trianguilar block is free to slide on a horizontal plane. Assume that all surfaces are frictionless. What is the acceleration of the mass M?

Homework Equations

F(net)=ma=0

The Attempt at a Solution

so basically i want to ask if my answer is correct, as I'm not familiar with this type of problem, i got:

F(horizontal) = mg cos $$\theta$$ sin $$\theta$$
a(M, horizontal) = F(horizontal) / (m + M)

is this right?

Not quite. Are the accelerations of the 2 blocks the same? What about the direction of the accelerations?