A rocket fires two engines simultaneously. One produces a thrust of 760N directly forward while the other gives a thrust of 484N at an angle 34.0 degrees above the forward direction.
What is the deviation of the direction (relative to the forward direction) of the resultant force which these engines exert on the rocket?
vertically
760 + 484cos(34) = 1161
then resolve horizontally
484sin(34)= 270.6
pythogoras theorem
Force= sqrt[(1161)^2)+(270.6^2) ]
F= 1192 North
can some one explain to me why cos is used in 760 + 484cos(34) = 1161 shouldn't it be sine if we are solving for the y component?
also I have trouble figuring out which quadrant to draw the triangle. I think its in the First quadrant but not sure.
Best Answer
Always, always, always start problems like this by drawing a diagram:
This make it obvious why cos and sin are used as they are.