... by using rectangular components.
Hello everyone! First post in this forum I hope I'll find what I'm looking for.
I'm home-studying Physics for the upcoming AS Level exams. Right now, I'm sort of stuck with understanding resultant forces. I've read about it in several books but none really explains what happens when adding the x and y components. Sometimes I solve the problems correctly and some other times, I just get stuck there not knowing what am I supposed to do next =|
I understand the steps of calculating but somewhere around calculating the horizontal and vertical components things start to get messed up
I don't think I fully understand how to calculate those because I don't get when to use sin or cos. Could someone please explain to me when to use the sin/cos or why sometimes it's in negative and sometimes it's positive ? Also at the very end when I find the direction of the resultant force, how can I tell if it's above the horizontal or below it or whatever it is supposed to be ?
Here is a problem I'm currently working on
http://i34.tinypic.com/5upjzs.jpgThanks alot in advance for any help