# Heavy uniform sphere - angle of friction?

• June 15th 2009, 12:34 PM
fardeen_gen
Heavy uniform sphere - angle of friction?
Show that the least force which applied to the surface of a heavy uniform sphere will just maintain it in equilibrium against a rough vertical wall is

$W\cos \epsilon$ or $W\tan \epsilon\left[\tan \epsilon - \sqrt{\tan^2 \epsilon - 1}\right]$

according as $\epsilon$ < or > $\arccos \frac{\sqrt{5} - 1}{2}$, where $W$ is the weight and $\epsilon$, the angle of friction.