Pulley and Mass on an Inclined Ramp

[theuniverse]

Homework Statement

A 20 kg mass is released, and the 5 kg mass on the ramp slides up the ramp from rest. As soon as the 5 kg mass gets to the end of the ramp, the string breaks down. What's the tension of the string?

http://img10.imageshack.us/img10/7603/figure1w.th.jpg

Homework Equations

I would use:
Fg=mg
Fnet = Fg1 + Fg2 + Ff
Fnet = ma
Fk = (uk)(Fn)

The question provies distances too, but I am not sure whether I actually need them...

The Attempt at a Solution

First I found the weight of both masses using Fg=mg
M1(on ramp) = 49N
M2 (hanging) = 196N

Then I found the components of Fg (and thus Fn), as shown in my diagram.
Fn = 42.4N
Therefore, using Fk = (uk)(Fn), I found the friction to be -11N.

I know that I have to calculate Fnet. So: Fnet = 196N -24.5N +11N = 182.5N
*Note: I am not very sure what sign does the friction have in this problem...

Not sure how to find tension from here... Fnet = Ft + Fgx + Ff?

Thank you for your time,

 

[Doc Al]

I recommend that you write separate force equations for each mass, then combine them. For the mass on the incline, consider forces parallel to the incline.

 

[theuniverse]

Thanks for replying.
I am not quite sure what you mean by separate force equations for each mass.
And wouldn't Fgx = 24.5N be the force parallel to the incline?

 

[Doc Al]

I am not quite sure what you mean by separate force equations for each mass.

Consider the forces on mass 1. Apply Newton's 2nd law. Do the same for mass 2.

And wouldn't Fgx = 24.5N be the force parallel to the incline?

That's the component of gravity on mass 1 parallel to the incline, but other forces act on that mass.