How Do I Solve Forces in Physics Problems Like 1d and 1e?

[SS2006]

http://img437.imageshack.us/img437/8104/untitled1wi.jpg
in 1 b) i know that the 4 N goes upwards

but in questions like 1 d or e, whta do i do then
for 1 d
1) -mgsin30 is going down, ok
and frictoin is going down, 2) -mgcos30u
ok
and the 8 N, is it 3) (8cos-30, 8sin-30)? if so, that's all good
but i get confused is what do i do with all these terms now
do i add them, 1) 2) 3) , i just wanted to know, the test is in an hour, need help asap :(
thx

 

[HallsofIvy]

http://img437.imageshack.us/img437/8104/untitled1wi.jpg
in 1 b) i know that the 4 N goes upwards
but in questions like 1 d or e, whta do i do then
for 1 d
1) -mgsin30 is going down, ok
and frictoin is going down, 2) -mgcos30u
ok
and the 8 N, is it 3) (8cos-30, 8sin-30)?

What exactly do you mean by "going down"? What you want to do is resolve the 8 N force into components parallel to and perpendicular to the ramp. The "8N" force will have components 8 cos(30) N up the ramp and
8 sin(30) N into the ramp. You will probably also want to calculate the component of weight into the ramp so you can use the sum of those two forces into the ramp to find the friction force (which is, of course, back down the ramp). The component of weight parallel to the ramp will be back down the ramp and it, along with the friction force, will subtract from the component of the 8 N up the ramp.

if so, that's all good
but i get confused is what do i do with all these terms now
do i add them, 1) 2) 3) , i just wanted to know, the test is in an hour, need help asap :(
thx

 

[SS2006]

i mean going dwon the x-y axis
u kow when u write up the ramp as a x-y axis
can you show me the final formula, of just one and how u arrived on the final answer, ill never get it until i see one
got all weekend tho that's good

 

[SS2006]

any help ppl
thanks

 

[Pyrrhus]

I'm not understanding what you are doing. In what questions do you hae problems, and what were your attempts?