A box of mass `8 kg ` placed on a rough inclined plane of inclened `theta` its downward motion can be prevented by applying an upward pull `F` and it can be made to slide upward appliying a force `2F` .The coefficient of friction between the box and the inclined plane is

A box of mass 8 kg placed on a rough inclined plane of inclination theta its downward motion can be prevented by applying an upward pull F and it can be made to slide upward appliying a force 2F .The coefficient of friction between the box and the inclined plane is

A box of mass 8 kg is placed on a rough inclined plane of inclination 45^(@) . Its downward motion c can be prevented by applying an upward pull F and it can be made to slide upwards by applying a force 2F. The coefficient of friction between the box and the inclined plane is