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The box is on the slope as in the picture. The angle of the slope is $\alpha$. The forces acting on the box are the force of gravity $\overrightarrow{F_G}$ and the friction $\overrightarrow{F_t}$. The force of gravity can be replaced by two components $\overrightarrow{F_1}$ and $\overrightarrow{F_n}$. (The force $\overrightarrow{F_1}$ is parallel to the slope and $\overrightarrow{F_n}$ is perpendicular to the slope.) The friction $F_t$ is given by the formula $F_t=f{F}_n$. The coefficient of the friction is $f=0.47$. Consider the standard acceleration of gravity $g=10\mathrm{m}{\mathrm{s}}^{-2}$. Find the angle $\alpha$ which ensures that the box moves on the slope with zero acceleration.