[tex]Se~da:\\ \\
m=1kg\\ \\
\alpha=30^\circ\\ \\
\mu=0,2\\ \\
g=10\frac m{s^2}\\ \\
F=?N\\ \\ \\
Formule:\\ \\
Ox:\\ \\
F+F_{fr}=G_{x}\\ \\
F+\mu\times N=G\times \sin \alpha\\ \\ \\
Oy:\\ \\
N=G_y\\ \\
N=G\times \cos\alpha\\ \\ \\
F+\mu\times G\times\cos\alpha=G\times\sin\alpha\\ \\
F=m\times g \times (\sin\alpha-\mu\times\cos\alpha)\\ \\ \\
Calcule:\\ \\
F=1\times10\times(\sin 30-0,2\times\cos 30)\approx 3,4N[/tex]
