Three forces of 5n, 7n, and 8n are applied to an object. If the object is in a state of equilibrium: calculate the angle between the lines of action of the 5 N and 7 N forces.

Question

anonymous · Answer

@agent0smith please help

agent0smith · Answer

I'll put the 7N force on the x axis just to make it a bit easier. |dw:1375853942625:dw|

All the horizontal and vertical components must add up to zero.

anonymous · Answer

thanks

agent0smith · Answer

Do you need more help? It looks like there might be a fair bit of work involved...

agent0smith · Answer

|dw:1375855964121:dw|
equating horizontal components gives:
$$\Large 8\cos A + 5\cos B = 7$$
equating vertical gives:
$$\Large 8\sin A = 5\sin B$$

agent0smith · Answer

Well, that looks like it'll be fun to solve... fair bit of trig.

Then you'll find the angle required by 180-B.

agent0smith · Answer

@eLg were you able to solve it?