A ladder 6 m long and weighs 120 N. It leans against a smooth wall of negligible friction making an angle of 50° with the horizontal. The coefficient of friction between the floor is 0.5. How far up the ladder can an 800 N worker climb before it starts to slip?
I ended up with the equation:
[itex]d*800\sin 40 = 0.5*2000*3*sin 50[/itex]