The diagram shows four coplanar forces of magnitude SN, RN, 60N and 80N acting at a point 0 in the direction shown.

http://http://www.mathhelpforum.com/...1&d=1230572234http://www.mathhelpforum.com/math-he...1&d=1230572234

Given the forces are in equilibrium, find the values of R and S.

I try to solve S

SNCOS60 = 60N

SN = 60/cos60

SN =120N

Try to solve R

RN + 120sin60 = 80N

RN = 80 - 120sin60

RN = -23.92

Can anybody spot a mistake? I'm sure you use SIN for forces up and down and COS for forces horizontally.