Posted by **LIZZIE** on Wednesday, February 27, 2013 at 6:54pm.

A particle of mass m rests on a rough inclined surface at an angle Pi/6

to the horizontal. When a force of magnitude P is applied parallel to the

surface pointing up the slope, the particle is on the point of slipping down the

slope, whereas when a force of magnitude 2P is applied parallel to the surface

pointing up the slope, the particle is on the point of slipping up the slope.

Show that the coecient of friction is

sqrt(3/9)?