[tex] \vec{G}=\vec{G_n}+\vec{G_t}\implies G_n=mg\cos\alpha, \:G_t=mg\sin\alpha [/tex]
Forta care poate pune in miscare corpul este asftel:
[tex] \vec{R}=\vec{F}+\vec{G_t}\implies R=\sqrt{F^2+m^2g^2\sin^2\alpha} [/tex]
Ca sa fie minima:
[tex] \vec{F_f}=-\vec{R}\implies \mu m g \cos\alpha=\sqrt{F^2+m^2g^2\sin^2\alpha} \\\\
\mu=\sqrt{\dfrac{F^2}{m^2 g^2\cos^2\alpha}+\dfrac{\sin^2\alpha}{\cos^2\alpha}} \\ \\ \mu=\sqrt{\dfrac{F^2+m^2g^2\sin^2\alpha}{m^2 g^2\cos^2\alpha}}=\dfrac{\sqrt{F^2+m^2g^2\sin^2\alpha}}{mg\cos\alpha}\approx 0,6981 [/tex]
