Newton's 2nd Law and drawing forces

[Manni]

Hey guys, how would I show that a = g sin(alpha) for the following diagram?

 

[LawrenceC]

You could start by drawing the forces on the block.

 

[Manni]

Yeah, I just figured it out.

I determined the Force acting about the hypotenuse, Fm

So, Fm = sin(alpha)*mg

Then, according to Newton's 2nd Law,

Fnet = Fm
ma = sin(alpha)*mg
a = g*sin(alpha)

N.B. The mass is assumed to be on a frictionless surface